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Home My WebLink About07-13-20 City Commission Packet Materials - OPH. Agency Exemption Hearing for Gallatin Co Fairgrounds App 20122 Commission Memorandum REPORT TO: Mayor and City Commission FROM: Danielle Garber, Associate Planner SUBJECT: Gallatin County Fairgrounds Surface Improvements Exemption Hearing, Application 20122 MEETING DATE: July 13, 2020 AGENDA ITEM TYPE: Other Public Hearing RECOMMENDATION: None. The City Commission shall have no power to deny the proposed use but shall act only to allow a public forum for comment on the proposed use per MCA 76-2-402. STRATEGIC PLAN: 1.3 Public Agencies Collaboration. Foster successful collaboration with other public agencies and build on these successes. BACKGROUND: Gallatin County has submitted a site plan application in order to make improvements to the Gallatin County Fairgrounds located on the north side of the City and generally bound by East Oak Street, North Rouse Avenue, and Tamarack Street. This site plan application proposes additional paving at the fairgrounds in order to reduce dust, increase stormwater control and compliance, increase pedestrian safety, and to allow better accommodation for the various uses on the multi-functional property. The project includes new paved parking and circulation areas for pedestrians, recreational vehicles, and passenger vehicles. The following changes are proposed with this application:  31 paved 12 foot x 24 foot RV parking spaces between the 1st and 2nd entrances off Tamarack detailed in figures 2 and 3.  23 paved 12 foot x 24 foot RV parking spaces between the 3rd and 4th entrances off Tamarack detailed in figures 2 and 3.  19 parking spaces south of the shooting range labeled “Main Entrance Parking” in the project proposal.  Paving for an exhibition area around the existing office and exhibit buildings detailed in figure 4.  Paving to the east and west of the rodeo grandstands detailed in figures 5 and 6. The DRC received an informal application in February 2020, application no. 20026, which was reviewed with the applicant in an in person meeting on March 4, 2020. The DRC letter provided the applicant advice and comments on this proposed project including the need for required grading and drainage improvements, site design elements including non-motorized circulation and design of pedestrian pathways, and several parking lot design requirements. This formal application in response to those comments reaffirmed the multifunctional nature of the fairgrounds and the desire to have diverse site use and layout options when accommodating 339 Commission Memorandum different events at the fairgrounds. In order to retain the most flexibility in the fairgrounds site usage, Gallatin County requests agency exemption from the following zoning standards per M.C.A. Section 76-3-402. The development proposal does not meet zoning standards for the following sections of the Bozeman Municipal Code (BMC): 1. BMC 38.410.080.H – Landscaping stormwater retention/detention facilities 2. BMC 38.520.040.B – Pedestrian access to sidewalk from all buildings 3. BMC 38.520.040.C.1 – Internal circulation between multiple buildings with pedestrian paths or walkways 4. BMC 38.520.040.C.4 – Pedestrian paths through parking lots 5. BMC 38.540.020.G – Striping of parking stalls 6. BMC 38.540.020.J – Parking lot curbing 7. BMC 38.540.020.L – Pedestrian facilities in parking lots 8. BMC 38.550.050.C – Parking lot landscaping. Montana law (M.C.A. Section 76-2-402) addresses the relationship of municipal zoning regulations to the Gallatin County Fairground’s use of land. The law requires a public hearing whenever land is to be used contrary to zoning regulations. The statute expressly provides that a municipality “shall have no power to deny the proposed use but shall act only to allow a public forum for comment on the proposed use.” For the reasons outlined in the attached staff report, eight exemptions have been requested to allow the addition of asphalt surfacing and parking areas without the required pedestrian facilities, curbing, striping, and landscaping improvements to the various effected areas. No public comment letters have been received as of the date this memo was written. The decision on the site plan application is under the authority of the Director of Community Development. Following the exemption hearing staff will finalize the review of the site plan application and forward on a recommendation for a Director decision. The City Commission is not the authority for the site plan application, but is the venue for any exemption claims hearings submitted per the M.C.A. UNRESOLVED ISSUES: None. ALTERNATIVES: 1. Conduct the required hearing as a forum for public comment on the proposed use per MCA 76-2-402. 2. As directed by the City Commission. FISCAL EFFECTS: Not applicable. Attachment: Staff Report 340 Commission Memorandum Application Report compiled on: July 2, 2020 341 Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 1 of 15 Project Name Gallatin County Fairgrounds Surface Improvements Exemption Hearing Application No. 20122 SP Site Plan Summary A site plan application is being submitted for the Gallatin County Fairgrounds. This project will include resurfacing six areas of the fairgrounds complex with asphalt including two RV parking areas along the south property line, a large exhibit area near the existing exhibit buildings and office, a parking area near the shooting range and two areas east and west of the rodeo grandstands. The proposed project also includes modifications to existing stormwater systems and surface grade to improve drainage. Gallatin County Fairgrounds proposed eight Agency Exemption(s) per Montana Code Annotated 76-2-402. Zoning PLI Growth Policy Public Lands and Institutions Parcel Size 64.73 acres Overlay District(s) None Street Address 901 North Black Avenue, Bozeman MT, 59715 Legal Description Imes Addition, S06, T02 S, R06 E, Acres 64.731, Part of Blocks 3 & 4 & All Blocks 5- 13 & 16-27 Plus Vacant Streets & Alleys Less Tract A, Plat C-41-D, City of Bozeman, Gallatin County, Montana. Owner Gallatin County Fairgrounds, 311 West Main St., Bozeman, MT 59715 Applicant Gallatin County Fairgrounds, Dennis Voeller, 311 West Main St., Bozeman, MT 59715 Representative Mike Russell, PE, Sanderson Stewart, 106 E. Babcock St., Bozeman, MT 59715 Staff Contacts Planner Danielle Garber Engineer Lance Lehigh Noticing Public Comment Period Site Posted Adjacent Owners Mailed Newspaper Legal Ad 6/28/20 – 7/13/20 6/28/20 NA 6/28/20 and 7/5/20 Venue: City Commission The meeting will EITHER be held in person in the City Commission Room, City Hall, 121 N. Rouse Avenue Bozeman, MT, OR be held using WebEx, an online video conferencing system. Hearing Date: Monday 7/13/20 6:00 pm Recommended Motion None. The City Commission shall have no power to deny the proposed use but shall act only to allow a public forum for comment on the proposed use per MCA 76-2-402. Full application and file of record: Community Development Department, 20 E. Olive St., Bozeman, MT 59715 Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 2 of 15 TABLE OF CONTENTS PROJECT SUMMARY .................................................................................................................................... 2 PUBLIC COMMENT ....................................................................................................................................... 4 UNRESOLVED ISSUES ................................................................................................................................... 4 MAP AND DRAWING SERIES ........................................................................................................................ 5 ANALYSIS AND FINDINGS ............................................................................................................................ 9 PROJECT SUMMARY This report is based on the application materials submitted and any public comment received to date. The City Commission receives the Gallatin County Fairgrounds Surface Improvements Site Plan application and conducts a public hearing on the agency exemptions the Fairgrounds is claiming under Montana Code Annotated (M.C.A.) Section 76-2-402.” Other than conducting a public hearing on the exemptions, no official motion is required by the City Commission. Gallatin County has submitted a site plan application in order to make improvements to the Gallatin County Fairgrounds located on the north side of the City and generally bound by East Oak Street, North Rouse Avenue, and Tamarack Street. This site plan application proposes additional paving at the fairgrounds in order to reduce dust, increase stormwater control and compliance, increase pedestrian safety, and to allow better accommodation for the various uses on the multi-functional property. A previous site plan approval called the Gallatin County Fairgrounds Asphalt Pathway site plan, application No. 19158, was approved on January 9, 2020. That project granted approval to pave with asphalt a 24-foot wide path over an existing gravel pathway between the parking area off Tamarack and the rodeo grandstand, no parking was proposed at that time. This application proposes additional paving for different functions and includes parking and circulation areas for pedestrians, and both recreational vehicles and passenger vehicles. The following changes are proposed with this application:  31 paved 12 foot x 24 foot RV parking spaces between the 1st and 2nd entrances off Tamarack detailed in figures 2 and 3.  23 paved 12 foot x 24 foot RV parking spaces between the 3rd and 4th entrances off Tamarack detailed in figures 2 and 3.  19 parking spaces south of the shooting range labeled “Main Entrance Parking” in the project proposal.  Paving for an exhibition area around the existing office and exhibit buildings detailed in figure 4.  Paving to the east and west of the rodeo grandstands detailed in figures 5 and 6. The DRC received an informal application in February 2020, application no. 20026, which was reviewed with the applicant in an in person meeting on March 4, 2020. The DRC letter provided the applicant advice and comments on this proposed project including the need for required grading and drainage improvements, site design elements including non-motorized circulation and design of pedestrian pathways, and several parking lot design requirements. This formal application in response to those comments requests agency exemption from the Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 3 of 15 following from compliance with certain zoning standards from M.C.A. Section 76-3-402. The development proposal does not meet zoning standards for the following sections of the Bozeman Municipal Code (BMC): 1. BMC 38.410.080.H – Landscaping stormwater retention/detention facilities 2. BMC 38.520.040.B – Pedestrian access to sidewalk from all buildings 3. BMC 38.520.040.C.1 – Internal circulation between multiple buildings with pedestrian paths or walkways 4. BMC 38.520.040.C.4 – Pedestrian paths through parking lots 5. BMC 38.540.020.G – Striping of parking stalls 6. BMC 38.540.020.J – Parking lot curbing 7. BMC 38.540.020.L – Pedestrian facilities in parking lots 8. BMC 38.550.050.C – Parking lot landscaping. Montana law (M.C.A. Section 76-2-402) addresses the relationship of municipal zoning regulations to the Gallatin County Fairground’s use of land. The law requires a public hearing whenever land is to be used contrary to zoning regulations. The statute expressly provides that a municipality “shall have no power to deny the proposed use but shall act only to allow a public forum for comment on the proposed use.” In this regard, the Fairgrounds is claiming exemptions to the Bozeman Municipal Code provisions, with provided rationale as follows: BMC 38.410.080.H – Landscaping stormwater retention/detention facilities: The exemption is requested from the requirement to make the stormwater facilities into landscaping amenities due to limited funding and the unique and special function of the fairgrounds site. The stormwater facility is intended to be a French drain system that can sustain vehicular traffic driving over it; the surface is proposed to be gravel. BMC 38.520.040.B – Pedestrian access to sidewalk from all buildings, BMC 38.520.040.C.1 – Internal circulation between multiple buildings with pedestrian paths or walkways, and BMC 38.520.040.C.4 – Pedestrian paths through parking lots: The exemption is requested from the site design requirements for non- motorized circulation and design because it is beyond the scope and the budget of the proposed project to provide access to all buildings, or to delineate pedestrian circulation routes between all buildings and through parking lots. The intent of the improvements is to improve surface conditions only, which will also improve the pedestrian experience. BMC 38.540.020.G – Striping of parking stalls, BMC 38.540.020.J – Parking lot curbing, and BMC 38.540.020.L – Pedestrian facilities in parking lots: The exemption is requested from the parking lot design requirements because the Fairgrounds has specific and unique needs in their exhibition areas for maximum flexibility in staging various events, uses, shows, and fair activities. Delineations such as curbing, landscape islands, striping, etc. will lessen flexibility and minimize the Fairgrounds ability to efficiently and effectively stage and manage fairground activities. BMC 38.550.050.C – Parking lot landscaping: The exemption is requested from the mandatory landscaping provisions for parking lot landscaping because of the unique uses that occur within the Fairgrounds property would limit their ability to effectively stage and manage activities. For these reasons, eight exemptions have been requested to allow the addition of asphalt surfacing and parking areas without the required pedestrian facilities, curbing, striping, and landscaping improvements to the various effected areas. Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 4 of 15 DECISION ON THE SITE PLAN APPLICATION The decision on the site plan application is under the authority of the Director of Community Development. Following the exemption hearing staff will finalize the review of the site plan application and forward on a recommendation for a Director decision. The City Commission is not the authority for the site plan application, but is the venue for any exemption claims hearings submitted per the M.C.A. ADVISORY BOARDS Not applicable PUBLIC COMMENT No public comment has been received as of the date this report was written. UNRESOLVED ISSUES There are no unresolved issues with the application. ATTACHMENTS  Application Documents  Application Plans  Public Comment if submitted. This application was received digitally in accordance with the City Manager’s Declaration of Emergency issued by the City on March 16, 2020. Online access to this application is available at https://www.bozeman.net/government/planning/using-the-planning-map. Select ‘Project Documents’ and navigate to application 20122 to view the full application. Digital access is also available at the Community Development Department at 20 E. Olive Street, Bozeman, MT 59715. Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 5 of 15 MAP AND DRAWING SERIES Figure 1: Vicinity Map Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 6 of 15 Figure 2: Overall Site Plan South – RV Parking, Main Entrance Parking & Exhibit Area Figure 3: Detailed Site Plan South – RV Parking and Main Entrance Parking Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 7 of 15 Figure 4: Detailed Site Plan South – Exhibition Area Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 8 of 15 Figure 5: Overall Site Plan North Figure 6: Detailed Site Plan North – West and East Grandstand Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 9 of 15 ANALYSIS AND FINDINGS Analysis and resulting recommendations are based on the entirety of the application materials, municipal codes, standards, plans, public comment, and all other materials available during the review period. Collectively this information is the record of the review. The analysis in this report is a summary of the completed review. Plan Review, Section 38.230.100, BMC In considering applications for plan approval under this title, the review authority shall consider the following: 1. Conformance to and consistency with the City’s adopted growth policy 38.100.040 B Meets Code? Growth Policy Land Use Public Lands and Institutions Yes Zoning PLI (Public Lands and Institutions) Yes Comments: The public institutions uses are allowed within the zoning district pursuant to Section 38.310 of the Bozeman Municipal Code. The property is within the City’s municipal service area and otherwise complies with the goals and objectives of the growth policy where applicable. Section 38.330.030 states “To the maximum extent allowed by state law, all PLI development must be subject to review and approval as provided for by this chapter, based upon recommendations received from the applicable review bodies established by article 2 of this chapter as may be applicable, and must be required to comply with all applicable underlying zoning requirements, as well as any requirements for certificates of appropriateness as established in design objective plans or other overlay district regulations or guidelines.” 2. Conformance to this chapter, including the cessation of any current violations 38.200.160 Meets Code? Current Violations None Yes Comments: The applicant is advised that unmet code provisions, or code provisions that are not specifically listed as conditions of approval, does not, in any way, create a waiver or other relaxation of the lawful requirements of the Bozeman Municipal Code or state law. 3. Conformance with all other applicable laws, ordinances, and regulations 38.100.080 Meets Code? Conflicts The following improvements do not meet zoning: The new surfacing of parking areas does not meet the requirements for pedestrian facilities, curbing, striping, and landscaping. Improvements to stormwater retention/detention facilities without landscaping improvements to make the facility a landscaped amenity. Surfacing improvements without the internal pedestrian circulation site design required between multiple buildings and to the public sidewalk. No Condominium ownership NA NA Comments: Design of the proposed surfacing improvements does not meet zoning requirements in eight sections of the Bozeman Municipal Code listed above in the Project Summary, and the City Commission must therefore act as the board of adjustments to hold a public hearing according to Montana Code Annotated 76- 2-402 (see statute language below). Montana Code Annotated 76-2-402. Local zoning regulations -- application to agencies. Whenever an agency proposes to use public land contrary to local zoning regulations, a public hearing, as defined below, shall be held. Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 10 of 15 (1) The local board of adjustments, as provided in this chapter, shall hold a hearing within 30 days of the date the agency gives notice to the board of its intent to develop land contrary to local zoning regulations. (2) The board shall have no power to deny the proposed use but shall act only to allow a public forum for comment on the proposed use. 4. Conformance with special review criteria for applicable permit types as specified in article 2 Meets Code? Type Site Plan Yes Comments: All other applicable site plan criteria are met for this application. 5. Conformance with zoning provisions of article 3 38.230.100 Meets Code? Permitted uses 38.310 Public and nonprofit, quasi-public institutions Yes Form and intensity standards 38.320 Yes Zoning PLI Setbacks (feet) Structures Parking / Loading Yes Front 0* 0* Rear 0* 0* Side 0 NA Alley NA NA Block Frontage Other / Landscaped Yes Comments: In the PLI district, there is no setback requirement except when a lot is adjacent to another district. The setbacks then must be the same as those in the adjacent district. The proposed surfacing improvements are largely internal to the site with the exception of the RV parking adjacent to the R-4 zoning district where an existing 20-foot setback is present which meets the minimum required in R-4. Relationship to adjacent properties standards 38.520.030 (light and air access and privacy) and angled setback plane 38.360.030 NA Applicable zone specific or overlay standards 38.330-340 NA Building Height PLI Requirements 38.320.010-.060 NA Height NA Allowed Unlimited Yes Comments: Not applicable, no new buildings are proposed. General land use standards and requirements 38.350 NA Applicable supplemental use criteria 38.360 NA Supplemental uses/type NA NA Comments: Not applicable, no general or supplemental land uses are proposed. 6a(1). Conformance with the community design provisions of article 4: Transportation facilities and access 38.400 Meets Code? Street vision NA NA Secondary access NA Traffic Impact Study / LOS NA Transportation grid adequate to serve site NA NA Comments: Not applicable, no access or use changes are proposed. Street dedication NA NA Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 11 of 15 Drive access locations and widths NA Number of drive accesses NA NA Street easements NA Special Improvement Districts NA NA Comments: Not applicable no access or public right of way changes are proposed. Parking requirements of 38.540 Required parking nonresidential NA NA Required parking residential NA Reductions nonresidential NA Reductions residential NA Provided parking off street NA On street parking NA Comments: Not applicable no use changes or minimum parking requirements are triggered with the proposed application. 6a(2). Conformance with the community design provisions of article 4: Pedestrian and vehicular ingress and egress 38.400 Meets Code? Design of the pedestrian and vehicular circulation systems to assure that pedestrians and vehicles can move safely and easily both within the site and between properties and activities within the neighborhood area No Vehicle accesses to site Multiple accesses existing NA Pedestrian access location(s) No Site vision triangles NA Fire lanes, curbs, signage and striping NA Non-automotive transportation and circulation systems, design features to enhance convenience and safety across parking lots and streets, including, but not limited to paving patterns, grade differences, landscaping and lighting No Crosswalks No Curb ramps No Pedestrian lighting NA Comments: The project does not propose changes to vehicular access or lighting. An exemption from pedestrian pathway design is proposed from Section 38.520 including pedestrian access to the public sidewalk from all buildings, pedestrian circulation between buildings, and pedestrian paths through parking lots. See 7a-c below. Adequate connection and integration of the pedestrian and vehicular transportation systems to the systems in adjacent development and the general community No Access easements NA NA Dedication of right-of-way or easements necessary for pedestrian, shared use pathway and similar transportation facilities NA Comments: The project does not propose any new right of way or access easements. An agency exemption has been requested from Section 38.520 including pedestrian integration into the existing sidewalk system. 6b Community design and element provisions 38.410 Meets Code? Lot and block standards 38.410.040 NA Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 12 of 15 Rights of way for pedestrians alternative block delineation NA Comments: Not applicable, no lot and block standards are triggered by the proposed project. Provisions for utilities including efficient public services and utilities 38.410.050-060 NA Municipal infrastructure requirements NA Easements (City and public utility rights-of-way etc.) NA Water, sewer, and stormwater NA Other utilities (electric, natural gas, communications) NA CIL of water NA Comments: Not applicable, no changes to municipal infrastructure are triggered by the proposed project. Site Surface Drainage and stormwater control 38.410.080 Yes Location, design and capacity Yes Landscaping per 38.410.080.H No Comments: Site surface drainage and stormwater control for the proposed project was reviewed by the Engineering Division and found to meet all drainage standards except landscaping as required by 38.410.080.H. An agency exemption from this landscaping standard is requested with this application. Grading 38.410.080 Yes Maximum 1:4 slope requirements met Yes Comments: Reviewed and approved by Engineering Division 7a-c. Conformance with the project design provisions of Article 5, Compatibility, Design and Arrangement Meets Code? Compatibility with, and sensitivity to, the immediate environment of the site and the adjacent neighborhoods and other approved development relative to architectural design, building mass, neighborhood identity, landscaping, historical character, orientation of buildings on the site and visual integration No Block Frontage Standards 38.510 NA Building Design 38.530 NA Location and design of service areas and mechanical equipment 38.520.070 NA Comments: An agency exemption from parking lot landscaping including screening from residential adjacency was requested from Section 38.550.050.C. Block frontage, building design, and mechanical equipment standards are not applicable to the proposed project. Design and arrangement of the elements of the plan (e.g., buildings, circulation, open space and landscaping, etc.) so that activities are integrated with the organizational scheme of the community, neighborhood, and other approved development and produce an efficient, functionally organized and cohesive development No Relationship to adjacent properties 38.520.030 NA Non-motorized circulation and design 38.520.040 No Vehicular circulation and parking 38.520.050 NA Comments: The project proposes agency exemptions from seven standards in Article 5. Where parking may be proposed and where site surfacing is proposed labeled Exhibition Area in the project proposal, exemptions from the following sections was requested:  BMC 38.520.040.B – Pedestrian access to a sidewalk from all buildings. This section requires that all buildings must feature pedestrian connections to a sidewalk along the block frontage. The intent of this section is to improve the pedestrian and bicycling environment by making it easier, safer, and more comfortable to walk or ride among residences, to businesses, to the street sidewalk, to transit stops, Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 13 of 15 through parking lots, to adjacent properties, and connections throughout the city, and to enhance access to on- and off-site areas and pedestrian/bicycle paths.  BMC 38.520.040.C.1 – Internal circulation between multiple buildings with pedestrian paths or walkways. For sites with multiple buildings, pedestrian paths or walkways connecting businesses and residential entries on the same development site must be provided. Routes that minimize walking distances must be utilized to the extent practical. Where parking areas are proposed for RVs along Tamarack, and passenger vehicles labeled Main Entrance Parking in the project proposal, exemptions from the following sections was requested:  BMC 38.540.020.G – Striping of parking stalls. All parking stalls must be marked with white or yellow painted lines not less than four inches wide, except for one- to four-household dwellings and individual townhouse/rowhouse units. An exception to this requirement may be approved by the city when the striping would otherwise be applied to an area that does not have a permanent and durable wearing surface.  BMC 38.540.020.J – Parking lot curbing. 1. All open off-street parking areas and drive aisles must have perimeter concrete curb around the entire parking lot, including driving access ways, except for individual townhouse/rowhouse units and one- to four-household dwellings. Continuous concrete curbing must be built according to standards provided by the review authority. Unless otherwise approved, the perimeter curb must be six-inch by six-inch concrete. 2. Concrete pin down wheel stops may be permitted as an alternative to continuous concrete curbing in front of parking spaces that front on the perimeter of the parking lot. However, continuous concrete curbing as described above must be provided in all situations where deemed necessary by the review authority to control drainage and soil erosion. 3. Alternative perimeter treatment may be permitted subject to the approval of the city engineer. 4. Requirements for perimeter curbing do not preclude shared access between adjacent parking lots.  BMC 38.540.020.L – Pedestrian facilities in parking lots. Concrete sidewalks a minimum of five feet in width must be provided between any existing or proposed building and adjacent parking lot. Where sidewalk curbs serve as wheel stops, an additional two feet of sidewalk width is required.  BMC 38.550.050.C – Mandatory landscaping provisions - Parking lot landscaping. All surface parking lots on the building site must be landscaped in accordance with this subsection C.2. a. Parking lot screening required (1) All parking lots located on a lot with a residential adjacency must be screened from that residential adjacency; (2) All parking lots located between a principal structure and a public street, must be screened from the public street; (3) The screening required under this subsection must be continuous and not less than four feet in width unless a different width is specified in 38.510.030; and (4) Screening must be maintained at a height of four to six feet except as otherwise restricted by fence and hedge height limits within required front setbacks and street vision triangles. b. Large canopy trees, large non- canopy trees or small trees must be provided in, or within 20 feet of, the parking lot at a minimum average density of: (1) One large canopy tree; or (2) One large non-canopy tree and one small tree; or (3) Three small trees for each nine parking spaces required or provided. c. No parking space shall be located more than 70 feet from the trunk of a tree. d. No tree shall be planted closer than three feet to the back of the curb or edging equivalent. Additionally, any parking lot providing 15 or more parking spaces must have a minimum of 20 square feet of landscape area within the parking lot for each off-street parking space in the lot provided as follows: (1) The interior parking lot landscaping must be designed to facilitate, control and denote proper vehicular circulation patterns; (2) Internal parking lot landscaping provided must be proportionately dispersed so as to define aisles and limit unbroken rows of parking to a maximum of 100 feet, with landscaped areas provided in an appropriate scale to the size of the parking Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 14 of 15 lot; and (3) The minimum width and/or length of any parking lot landscaped area is eight feet. No landscape area may be less than two feet wide. (4) All parking lots under this subsection must include at least one large canopy or non-canopy tree. (5) Individual internal parking lot landscaping areas with minimum dimensions of six feet by 16 feet must include large canopy or non-canopy tree(s). The intent of the mandatory landscaping provisions includes these specific purposes: 1. To aid in stabilizing the environment's ecological balance by contributing to the process of air purification, oxygen regeneration, groundwater recharge, stormwater runoff retardation, and improvement of water quality, while at the same time aiding in noise, glare and heat abatement; 2. To provide visual buffering between land uses of differing character by placing screening vegetation; and 3. To enhance the beauty of the city by expanding and strengthening the urban forest and providing a diversity of vegetation within the city. Design and arrangement of elements of the plan (e.g., buildings circulation, open space and landscaping, etc.) in harmony with the existing natural topography, natural water bodies and water courses, existing vegetation, and to contribute to the overall aesthetic quality of the site configuration NA Site Planning and Design Elements 38.520 No Comments: See above requested exemptions. 7d. Conformance with the project design provisions of Article 5, Landscaping including the enhancement of buildings, appearance of vehicular use, open space and pedestrian area and the preservation of replacement of natural vegetation Meets Code? Submittal requirements for landscape plans 38.220.100 NA Mandatory landscaping 38.550.050 No Yard NA Additional screening NA Parking lot screening No Interior parking lot landscape No Off-street loading spaces screening NA Street frontage NA Street median island NA Acceptable landscape materials NA Protection of landscape areas NA Irrigation: plan, water source, system type NA Trees for residential adjacency NA City rights-of-way and parks NA Tree plantings for boulevard ROW, drought-resistant seed NA Public ROW boulevard strips NA Irrigation and maintenance provisions for ROW NA State ROW landscaping NA Additional NA NA Fencing and walls NA NA Comments: Existing street frontage landscaping complies with requirements. Exemptions as detailed above from the parking lot screening and interior parking lot landscaping were requested. Site planning and design required 38.520 No Pedestrian area landscaping, including pathways and internal circulation 38.520.040 No Staff Report Gallatin County Fairgrounds Surface Improvements Site Plan (SP) Application: 20122 Prepared July 2, 2020 Page 15 of 15 Internal roadway landscaping 38.520.050 NA Open space landscaping 38.520.060 NA Service area and mechanical equipment landscaping and screening 38.520.070 NA Comments: Exemptions as detailed above from parts of the site planning and design section including pedestrian areas was requested. 7f. Conformance with the project design provisions of Article 5, Lighting 38.570 Meets Code? Building-mounted lighting (cutoff and temperature) NA Site lighting (supports, cutoff and temperature) NA Minimum light trespass at property line NA Comments: Not applicable, no lighting is proposed. 8a-c. Conformance with environmental and open space objectives in articles 4-6 Meets Code? Enhancement of natural environment NA Grading Yes On-site retention/detention Yes Comments: Project meets requirements. Drainage design Yes Stormwater maintenance plan 38.410.030.A Yes Stormwater feature: landscaping amenity, native species, curvilinear, 75% live vegetation No Comments: Stormwater detention and other proposed facilities were reviewed and approved by Engineering for basic capacity and structural compliance. An agency exemption has been requested from 38.410.080.H, which requires landscaping of stormwater retention/detention facilities. Watercourse and wetland protections and associated wildlife habitats NA If the development is adjacent to an existing or approved public park or public open space area, have provisions been made in the plan to avoid interfering with public access to and use of that area NA Comments: Not applicable, no watercourses, wetlands or wildlife habitats are effected by the proposed project. No public parks or open spaces are proposed or adjacent to the project. A1 DEVELOPMENT REVIEW APPLICATION PROJECT IMAGE PROJECT INFORMATION Project name: Project type(s): Description: Street address: Zip code: Zoning: Gross lot area: Block frontage: Number of buildings: Type and Number of dwellings: Non-residential building size(s): (in stories) Non-residential building height(s): Number of parking spaces: Afordable housing (Y/N): Cash in lieu of parkland (Y/N): VICINITY MAP CITY USE ONLY Submittal date: Application fle number: Planner: DRC required (Y/N): Revision Date: Development Review Application A1 Page 1 of 3 Revision Date: 5.16.18 REQUIRED FORMS: Varies by project type, PLS 342 DEVELOPMENT REVIEW APPLICATION 1. PROPERTY OWNER Name: Full address (with zip code): Phone: Email: 2. APPLICANT Name: Full address (with zip code): Phone: Email: 3. REPRESENTATIVE Name: Full address (with zip code): Phone: Email: 4. SPECIAL DISTRICTS Overlay District: Neighborhood Conservation None Urban Renewal District: Downtown North 7th Avenue Northeast North Park None 5. CERTIFICATIONS AND SIGNATURES This application must be signed by both the applicant(s) and the property owner(s) (if diferent) for all application types before the submittal will be accepted. The only exception to this is an informal review application that may be signed by the applicant(s) only. As indicated by the signature(s) below, the applicant(s) and property owner(s) submit this application for review under the terms and provisions of the Bozeman Municipal Code. It is further indicated that any work undertaken to complete a development approved by the City of Bozeman shall be in conformance with the requirements of the Bozeman Municipal Code and any special conditions established by the approval authority. I acknowledge that the City has an Impact Fee Program and impact fees may be assessed for my project. Further, I agree to grant City personnel and other review agency representative’s access to the subject site during the course of the review process (Section 38.34.050, BMC). I (We) hereby certify that the above information is true and correct to the best of my (our) knowledge. Certifcation of Completion and Compliance – I understand that conditions of approval may be applied to the application and that I will comply with any conditions of approval or make necessary corrections to the application materials in order to comply with municipal code provisions. Statement of Intent to Construct According to the Final Plan – I acknowledge that construction not in compliance with the approved fnal plan may result in delays of occupancy or costs to correct noncompliance. continued on next page Development Review Application A1 Page 2 of 3 Revision Date: 5.16.18 REQUIRED FORMS: Varies by project type, PLS 343 344 N1 Noticing Materials Page 1 of 1 Revision Date 03-07-18 Required Forms: N1 Recommended Forms: Required Forms: NOTICING MATERIALS Notice is required for certain projects in order for citizens to participate in decision making which affects their interests and provides opportunity to receive information pertinent to an application that would not otherwise be available to the decision maker. SITE PLAN, MASTER SITE PLAN, CONDITIONAL USE PERMIT, VARIANCE, DEVIATION, FIRST MINOR SUBDIVISON AND SIMILAR REQUIRED NOTICING MATERIALS Completed and signed property adjoiners certificate form N1. Legible list of full names and addresses of all property owners within 200 feet of the project site, attached to this checklist. Stamped, unsealed, plain (no return address) #10 envelopes preaddressed with the names and addresses of the adjoining property owners. MAJOR AND SUBSEQUENT MINOR SUBDIVISION REQUIRED NOTICING MATERIALS Completed and signed property adjoiners certificate form N1. Legible list of full names and addresses of all property owners within 200 feet of the project site and not physically contiguous (touching a boundary) to the subdivision, attached to this checklist. Clearly label list ADJOINER NOT CONTIGUOUS. Stamped, unsealed, plain (no return address) #10 envelopes preaddressed with the names and addresses of the adjoining property owners. Legible list of full names and addresses of all property owners physically contiguous (touching a boundary) including recorded purchasers under contract for deed to be sent certified mail attached to this checklist. Clearly label list CONTIGUOUS. Stamped, unsealed, plain (no return address) #10 envelopes preaddressed with the names and addresses of the physically contiguous property owners including recorded purchasers under contract for deed. Two sets additional mailing labels with the names and addresses of the physically contiguous property owners including recorded purchasers under contract for deed attached. NOTICE Current property owners of record can be found at the Gallatin County Clerk and Recorder’s Office in the Gallatin County Courthouse 311 West Main Street Bozeman, Montana. CERTIFICATION I, _____________________________________________, hereby certify that, to the best of my knowledge, the attached name and address list of all adjoining property owners (including all condominium owners, within 200 feet of the property located at ________________________________________________________, is a true and accurate list from the last declared Gallatin County tax records. I further understand that an inaccurate list may delay review of the project. _______________________________________ Signature CONTACT US Alfred M. Stiff Professional Building 20 East Olive Street 59715 (FED EX and UPS Only) PO Box 1230 Bozeman, MT 59771 phone 406-582-2260 fax 406-582-2263 planning@bozeman.net www.bozeman.net X X X Michael T. Russell 901 North Black Avenue, Bozeman, MT 59715 NA NA NA NA NA NA 345 Gallatin Fairground Improvements Site Plan Review Certificate of Subdivision C-41-C Adjacent Property Owners Legal Description Property Owner's Name Street City State 1 MINOR SUB 109C, S01, T02 S, R05 E, Lot 1A, ACRES 27.604, (IMPS ON RGG32262) WESTLAKE GEORGE E & DK MARTINEN LLC 702 SW 8TH STREET C/O WALMART STORES INC BENTONVILLE, AR 72712-8050 2 S06, T02 S, R06 E, SW4NW4 S OF RW LESS SE COR & HW & MS109C 18.249AC WESTLAKE GEORGE E & DK MARTINEN LLC 15008 SE GRAHAM RD VANCOUVER, WA 98683-8541 3 BUILDING N CONDO, S06, T02 S, R06 E, IMES ADD LOT N PLAT C-41-M BUILDING N CONDO MASTER 105 E OAK STREET BOZEMAN, MT 59718-9999 4 IMES ADD, S06, T02 S, R06 E, Lot 1,3 &4, ACRES 6.665, COMMON OPEN SPACES PLAT C-41-M CANNERY DISTRICT PROPERTY OWNERS ASSOCIATION 113 E OAK ST STE 4A BOZEMAN, MT 59715-2974 5 IMES ADD, S06, T02 S, R06 E, Lot F, ACRES 0.3484, PLAT C-41-M CANNERY DISTRICT PARTNERS LLC 113 E OAK ST STE 4A BOZEMAN, MT 59715-2974 6 IMES ADD, S06, T02 S, R06 E, Lot K, ACRES 0.28949, PLAT C-41-M BOISE AIRPORT CENTER LLC 113 E OAK ST STE 4A BOZEMAN, MT 59715-2974 7 IMES ADD, S06, T02 S, R06 E, Lot 2, COMMON OPEN SPACE PLAT C-41-M CANNERY DISTRICT PROPERTY OWNERS ASSOCIATION 113 E OAK ST STE 4A BOZEMAN, MT 59715-2974 8 IMES ADD, S06, T02 S, R06 E, Lot J, ACRES 0.45468, PLAT C-41-M CANNERY DISTRICT PARTNERS LLC 113 E OAK ST STE 4A BOZEMAN, MT 59715-2974 9 MINOR SUB 391, S06, T02 S, R06 E, Lot 4, PLUS % OF COMMON AREA TURCZYN JUMP LLC 2712 DAISY DR BOZEMAN, MT 59718-6024 10 MINOR SUB 391B, S06, T02 S, R06 E, Lot 5A, COMMON AREA NORTHSIDE PROPERTY OWNERS ASSOC 1006 W MAIN ST BOZEMAN, MT 59715-3219 11 IMES ADD, S06, T02 S, R06 E, ACRES 7.831, PARCEL A PLAT C-41-L CITY OF BOZEMAN PO BOX 1230 BOZEMAN, MT 59771-1230 12 IMES ADD, S06, T02 S, R06 E, BLOCK 29, Lot 1-10 & 13 - 24, PLAT C-41 LESS HWRW CITY OF BOZEMAN PO BOX 1230 BOZEMAN, MT 59771-1230 13 IMES ADD, S06, T02 S, R06 E, BLOCK 30, PLAT C- 41 CITY OF BOZEMAN PO BOX 1230 BOZEMAN, MT 59771-1230 14 IMES ADD, S06, T02 S, R06 E, BLOCK 31, Lot 1 - 2, ACRES 0.184, PLAT C-41 BAUERLE PATRICIA L 201 E SOUTHVIEW AVE BELGRADE, MT 59714-3844 15 IMES ADD, S06, T02 S, R06 E, BLOCK 31, Lot 3 - 4, ACRES 0.183, PLAT C-41 RICHARDSON SCOTT H & SALLY S 2 GALLATIN DR APT B BOZEMAN, MT 59718-1515 16 IMES ADD, S06, T02 S, R06 E, BLOCK 31, Lot 5 - 6, ACRES 0.183, PLAT C-41 CHASE ANNE GILBERT & THOMPSON JASON NEIL 815 N BOZEMAN AVE BOZEMAN, MT 59715-2954 17 IMES ADD, S06, T02 S, R06 E, BLOCK 31, Lot 21 - 24, ACRES 0.441, N 20' LOT 20, PLAT C-41 822 NORTH BLACK LLC 11 LARIAT LOOP BOZEMAN, MT 59715-9200 18 IMES ADD, S06, T02 S, R06 E, BLOCK 31, Lot 18 - 19, ACRES 0.22, N 5' LOT 17 & S 5' LOT 20, PLAT C-41 113 LLC PO BOX 573 BOZEMAN, MT 59771-0573 19 IMES ADD, S06, T02 S, R06 E, BLOCK 32, Lot 1 - 2, ACRES 0.227, N 20' LOT 3, PLAT C-41 KOLLER LAUREL & PAUL T & SHERMAN EMILY 20 E TAMARACK ST BOZEMAN, MT 59715-2983 20 IMES ADD, S06, T02 S, R06 E, BLOCK 32, Lot 4 - 6, ACRES 0.308, S 5' LOT 3 & N 15' LOT 7, PLAT C- 41 SCHUTZ JASON 815 N BLACK AVE BOZEMAN, MT 59715-2907 21 IMES ADD, S06, T02 S, R06 E, BLOCK 32, Lot 23 - 24, ACRES 0.162, PLAT C-41 ERHARDT CASSANDRA 4 E TAMARACK ST BOZEMAN, MT 59715-2913 22 IMES ADD, S06, T02 S, R06 E, BLOCK 32, Lot 21 - 22, ACRES 0.162, PLAT C-41 MANGOLD KRISTOPHER G & JANE M 820 N TRACY AVE BOZEMAN, MT 59715-2814 23 IMES ADD, S06, T02 S, R06 E, BLOCK 32, Lot 19 - 20, ACRES 0.162, PLAT C-41 GEISE BOBBI J 3475 TUMBLEWEED DR BOZEMAN, MT 59715-8401 24 IMES ADD, S06, T02 S, R06 E, TRACT 1, C.O.S. 428 CITY OF BOZEMAN PO BOX 1230 BOZEMAN, MT 59771-1230 25 IMES ADD, S06, T02 S, R06 E, ACRES 3.07, TRACT 2, C.O.S. 428 GREENWOOD ENTERPRISES LLC PO BOX 788 BOZEMAN, MT 59771-0788 26 IMES ADD, S06, T02 S, R06 E, BLOCK 35, Lot 1 - 2, ACRES 0.115, PLAT C-41 DRYSDALE FAMILY LLC 511 PERKINS PL BOZEMAN, MT 59715-3738 346 Gallatin Fairground Improvements Site Plan Review Certificate of Subdivision C-41-C Adjacent Property Owners 27 IMES ADD, S06, T02 S, R06 E, BLOCK 35, Lot 3 - 4, ACRES 0.115, PLAT C-41 LODGE SHARON 235 CIRQUE DR BOZEMAN, MT 59718-9315 28 IMES ADD, S06, T02 S, R06 E, BLOCK 35, Lot 5 - 6, ACRES 0.115, PLAT C-41 RIEDERS NATHANIEL F 815 N GRAND AVE BOZEMAN, MT 59715-2807 29 IMES ADD, S06, T02 S, R06 E, BLOCK 35, Lot 23 - 24, ACRES 0.122, PLAT C-41 MANGELS ANGIE J 824 N 3RD AVE BOZEMAN, MT 59715-2845 30 IMES ADD, S06, T02 S, R06 E, BLOCK 35, Lot 21 - 22, ACRES 0.123, PLAT C-41 GROTH FLORENCE 3300 E GRAF ST UNIT 24 BOZEMAN, MT 59715-7185 31 IMES ADD, S06, T02 S, R06 E, BLOCK 35, Lot 19 - 20, ACRES 0.122, PLAT C-41 OUELLETTE GUY K 814 N 3RD AVE BOZEMAN, MT 59715-2845 32 HOMESTEAD TOWNHOUSES PH 1, S01, T02 S, R05 E, BLOCK 1, Lot 506, ACRES 0.062, PLUS INT IN PRIVATE RD & COMMON AREA, PLAT J-134 TACK ELEANOR 506 IVAN DR BOZEMAN, MT 59715-7211 33 HOMESTEAD TOWNHOUSES PH 1, S01, T02 S, R05 E, BLOCK 1, Lot 504, ACRES 0.062, PLUS INT IN PRIVATE RD & COMMON AREA, PLAT J-134 JUST ONE MORE LLC 716 N 3RD AVE BOZEMAN, MT 59715-2844 34 HOMESTEAD TOWNHOUSES PH 1, S01, T02 S, R05 E, BLOCK 1, Lot 502, ACRES 0.062, PLUS INT IN PRIVATE RD & COMMON AREA, PLAT J-134 TOOMEY PAUL 502 IVAN AVE BOZEMAN, MT 59715 35 HOMESTEAD TOWNHOUSES PH 1, S01, T02 S, R05 E, BLOCK 1, Lot 503, ACRES 0.062, PLUS INT IN PRIVATE RD & COMMON AREA, PLAT J-134 BOWERS RHONDA JEAN 503 IVAN DR BOZEMAN, MT 59715-7212 36 HOMESTEAD TOWNHOUSES PH 1, S01, T02 S, R05 E, BLOCK 1, Lot 505, ACRES 0.062, PLUS INT IN PRIVATE RD & COMMON AREA, PLAT J-134 STEVE W KISTLER 505 IVAN AVE BOZEMAN, MT 59715 37 HOMESTEAD TOWNHOUSES PH 1, S01, T02 S, R05 E, BLOCK 1, Lot 507, ACRES 0.062, PLUS INT IN PRIVATE RD & COMMON AREA, PLAT J-134 CLEM BOBBI TURNQUIST 4243 W BABCOCK ST UNIT 4 BOZEMAN, MT 59718-1603 38 WESTLAKES 4TH ADD, S01, T02 S, R05 E, BLOCK 2, ACRES 10.4 WESTLAKE GEORGE E & DK MARTINEN LLC 15008 SE GRAHAM RD VANCOUVER, WA 98683-8541 39 WESTLAKES 4TH ADD, S01, T02 S, R05 E, BLOCK 3, ACRES 8.63 WESTLAKE GEORGE E & DK MARTINEN LLC 15008 SE GRAHAM RD VANCOUVER, WA 98683-8541 347 348 349 350 351 352 353 354 May 14, 2020 (Updates in blue bold type, below) City of Bozeman – Planning Department 20 East Olive Street Bozeman, MT 59715 Reference: Gallatin County Fairgrounds Surface Improvements Application No. TBD SP1 Application Project No. BOZ-13005.04 Dear Planning and Engineering Review Staff: We are happy to submit the following SP1 Application for the Gallatin County Fairgrounds Surface Improvements project. The purpose of this narrative is to describe the extent of this project. We recognize and acknowledge that City reviewing staff has recommended the submittal of an MSP for the Fairgrounds property but Sanderson Stewart has not been authorized by Gallatin County to produce Master Site Plan materials at this time. With this submittal, the Gallatin County Fairgrounds requests agency exemption for the following code sections. City comments in the informal application #20026 are provided below with resonses: · 38.410.080 - Gallatin County Fairgrounds requests exemption from the above-requirement to make stormwater facilities into landscaping amenities due to limited funding and the fairgrounds serving a unique and special function. The stormwater facility is intended to be a french drain system that can sustain vehicular traffic driving over it, so the surface is proposed to be gravel. 355 2 · 38.520.040 - Gallatin County Fairgrounds requests exemption from the above-requirement, related to non-motorized circulation and design. It is beyond the scope and budget of the proposed project (surface improvements in various parts of the fairgrounds) to provide access to all buildings, or to delineate pedestrian circulation routes between all buildings and through parking lots. The intent of the improvements is to improve surface conditions, which will in some ways improve the pedestrian experience during certain events relative to the current, existing conditions. 356 3 · 38.540.020 - Gallatin County Fairgrounds requests exemption from the above-requirement, related to parking lot design. The Fairgrounds has specific and unique needs in their exhibition areas for maximum flexibility in staging various events, uses, shows, and fair activities. Delineations such as curbing, landscape islands, striping, etc. will lessen flexibility and minimize the Fairgrounds ability to efficiently and effectively stage and manage Fairgrounds activities. · 38.540.050.C - Gallatin County Fairgrounds requests exemption from the above- requirement, related to landscaping. As described in previous code section exemption requests, the unique uses that occur within Fairgrounds property means that full compliance with this Landscaping ordinance would limit the Fairgrounds’ ability to effectively stage and manage Fairground activities. Site Background & Tie-in to Previous Asphalt Pathways Project The Gallatin County Fairgrounds Surface Improvements project is at the Fairgrounds complex located off West Tamarack Street in Bozeman, Montana. Plans are provided in the attachments of this application, which show the extents of each of the desired areas of surface improvements. The intent is to use an on-site stockpile of recycled asphalt pavement material to “clean up” the identified areas. Stormwater facilities proposed in the previous “Asphalt Pathways” project were sized conservatively, assuming the entire area upstream (to the south) could be improved to asphalt paving. Calculations from the previous “Asphalt Pathways” project are included in this submittal. Currently, the Fairgrounds are permitted to construct the Asphalt Pathways project (Application #19158) that was approved by the City of Bozeman on January 10, 2020. The Gallatin Fairgrounds Asphalt Pathways project included paving and stormwater improvements to existing gravel travel ways within the Fairgrounds Complex. The project will include re-grading and new asphalt paving of existing gravel areas to the south and west of the Haynes Pavilion building and south of the rodeo grandstands. The project includes modifications to existing stormwater structures and surface grades to improve drainage around buildings. It also proposes improvements to existing drainage paths and installation of new drywells and a detention pond in order to reduce the amount of runoff that flows into the City right-of-way. An underground boulder pit will also be constructed along the southern edge of asphalt of the new paved pathway. This proposed boulder pit was sized with the assumption that further paving improvements could be constructed (to the south), as proposed in this SP1 Application. The proposed surface improvements are described below: Proposed Surface Improvements West and East Grandstand Improvements – Sheet C3.3 As shown on Sheet C3.3, surface improvements are proposed to the east and west side of the Anderson Arena grandstands. The hatch shows the approximate extents of the improvements, which will include re-surfacing the area with recycled asphalt material that is stockpiled on the site. 357 4 Increased runoff to the west will be directed towards the existing drainage swale located along the southern and western edge of the proposed improvements. Increased runoff to the east will be sheeted towards the drainage swale and retaining pond to the north that will be constructed with the Asphalt Pathways project. RV Parking Between 1st and 2nd Entrances – Sheet C3.3 Currently, RV parking is provided between the 1st and 2nd entrances along West Tamarack Street in the gravel lot. The proposed hatch shows the extents of re-surfacing this RV parking area with recycled asphalt material. RV Parking Between 3rd and 4th Entrances – Sheet C3.3 RV parking is also provided between the 3rd and 4th entrances along West Tamarack Street in the Tamarack Parking Lot. Similar to the previously proposed improvements, the proposed hatch shows the approximate extents of re-surfacing the RV parking with recycled asphalt material. Main Entrance Parking – Sheet C3.3 Handicap parking is provided at the main entrance to the fairgrounds, which is to the south of the indoor shooting range and County Weed Department office. This parking area is currently gravel and is proposed to be re-surfaced with recycled asphalt material. This will help to improve drainage in this area, and also bring the area up to ADA standards. Exhibition Area – Sheet C3.4 Sheet C3.4 shows the approximate extents of the proposed surface improvements to the exhibition area. This area is largely used for booth setups during fairground events and is rarely used for parking. Again, it is the intent to utilize the recycled asphalt material to re-surface the area, but stormwater facilities were sized assuming a full pave out. If you need any additional information for this SP1 Application, please let me know. Sincerely, Mike Russell, PE, MBA Project Manager Sanderson Stewart 358 359 CP#10 CP#9 CP#8 PROJECT SURVEY CONTROL Point # 1 7 8 9 10 47002 Northing 129966.11 130055.46 130543.31 130582.56 130686.84 129942.28 Easting 365103.66 364973.44 364944.18 365176.86 365017.88 365408.34 Elevation 4765.63 4764.73 4759.03 4758.23 4757.49 4766.15 Description CP 1"DIA NAIL CP / 2"ACR.SSCTLMON CP / 2"ACR.SSCTLMON CP / MAG NAIL CP / HUB & TACK CP 5 SP1 SUBMITTALNORTH NOTE: -EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS. -ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OF BOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM. -UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED IN THE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES AS ARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED.FILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTIONIMES ADDITION, PLAT C-41-DOVERALL EXISTING SITE - NORTHGALLATIN COUNTY FAIRGROUNDSDESIGN FOR SURFACE IMPROVEMENTSBOZEMAN, MTC2.1 -BOZ_13005_04_EX_PROD.DWGJAZ01/22/20INF SUBMITTAL04/01/2004/29/20----SP1 1ST SUBMITTALSP1 2ND SUBMITTAL------BOZ-13005.04ELECTRIC JUNCTION BOX EXISTING TELEPHONE SIGN EXISTING SANITARY SEWER EXISTING STORM DRAIN POWER POLE WATER VALVE FIRE HYDRANT EXISTING GAS EXISTING POWER EXISTING OVERHEAD POWER LINE TYPICAL BOLLARD IRRIGATION VALVE LIGHT POLE POWER METER SANITARY SEWER MANHOLE TELEPHONE PEDESTAL TRANSFORMER DECIDUOUS TREE EXISTING FIBER OPTIC EXISTING WATER EXISTING CONTOURS LEGEND PROJECT DATUM: HORIZONTAL NAD 83, VERTICAL NAD 88 SURVEYED: FALL 2014, SPRING 2015, MAY 2018, OCTOBER 2019 BY: SANDERSON STEWART CONIFEROUS TREE 360 CP#7 CP#47002 CP#1 SP1 SUBMITTALNORTH NOTE: -EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS. -ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OF BOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM. -UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED IN THE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES AS ARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED.FILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTIONIMES ADDITION, PLAT C-41-DOVERALL EXISTING SITE - SOUTHGALLATIN COUNTY FAIRGROUNDSDESIGN FOR SURFACE IMPROVEMENTSBOZEMAN, MTC2.2 -BOZ_13005_04_EX_PROD.DWGJAZ01/22/20INF SUBMITTAL04/01/2004/29/20----SP1 1ST SUBMITTALSP1 2ND SUBMITTAL------BOZ-13005.04ELECTRIC JUNCTION BOX EXISTING TELEPHONE SIGN EXISTING SANITARY SEWER EXISTING STORM DRAIN POWER POLE WATER VALVE FIRE HYDRANT EXISTING GAS EXISTING POWER EXISTING OVERHEAD POWER LINE TYPICAL BOLLARD IRRIGATION VALVE LIGHT POLE POWER METER SANITARY SEWER MANHOLE TELEPHONE PEDESTAL TRANSFORMER DECIDUOUS TREE EXISTING FIBER OPTIC EXISTING WATER EXISTING CONTOURS LEGEND CONIFEROUS TREE 361 SP1 SUBMITTALNORTH NOTE: -EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS. -ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OF BOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM. -UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED IN THE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES AS ARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED.FILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTIONIMES ADDITION, PLAT C-41-DOVERALL SITE PLAN - NORTHGALLATIN COUNTY FAIRGROUNDSDESIGN FOR SURFACE IMPROVEMENTSBOZEMAN, MTC3.1 -BOZ_13005_04_SITE_PROD.DWGJAZ01/22/20INF SUBMITTAL04/01/2004/29/20----SP1 1ST SUBMITTALSP1 2ND SUBMITTAL------BOZ-13005.04ELECTRIC JUNCTION BOX EXISTING TELEPHONE SIGN EXISTING SANITARY SEWER EXISTING STORM DRAIN POWER POLE WATER VALVE FIRE HYDRANT EXISTING GAS EXISTING POWER EXISTING OVERHEAD POWER LINE TYPICAL BOLLARD IRRIGATION VALVE LIGHT POLE POWER METER SANITARY SEWER MANHOLE TELEPHONE PEDESTAL TRANSFORMER DECIDUOUS TREE EXISTING FIBER OPTIC EXISTING WATER EXISTING CONTOURS LEGEND CONIFEROUS TREE 362 SP1 SUBMITTALNORTH NOTE: -EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS. -ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OF BOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM. -UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED IN THE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES AS ARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED.FILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTIONIMES ADDITION, PLAT C-41-DOVERALL SITE PLAN - SOUTHGALLATIN COUNTY FAIRGROUNDSDESIGN FOR SURFACE IMPROVEMENTSBOZEMAN, MTC3.2 -BOZ_13005_04_SITE_PROD.DWGJAZ01/22/20INF SUBMITTAL04/01/2004/29/20----SP1 1ST SUBMITTALSP1 2ND SUBMITTAL------BOZ-13005.04ELECTRIC JUNCTION BOX EXISTING TELEPHONE SIGN EXISTING SANITARY SEWER EXISTING STORM DRAIN POWER POLE WATER VALVE FIRE HYDRANT EXISTING GAS EXISTING POWER EXISTING OVERHEAD POWER LINE TYPICAL BOLLARD IRRIGATION VALVE LIGHT POLE POWER METER SANITARY SEWER MANHOLE TELEPHONE PEDESTAL TRANSFORMER DECIDUOUS TREE EXISTING FIBER OPTIC EXISTING WATER EXISTING CONTOURS LEGEND CONIFEROUS TREE 363 SP1 SUBMITTALNORTH NOTE: -EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS. -ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OF BOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM. -UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED IN THE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES AS ARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED.FILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTIONIMES ADDITION, PLAT C-41-DSITE & DIMENSION PLANGALLATIN COUNTY FAIRGROUNDSDESIGN FOR SURFACE IMPROVEMENTSBOZEMAN, MTC3.3 -BOZ_13005_04_SITE_PROD.DWGJAZ01/22/20INF SUBMITTAL04/01/2004/29/20----SP1 1ST SUBMITTALSP1 2ND SUBMITTAL------BOZ-13005.04EXISTING TELEPHONE EXISTING SANITARY SEWER EXISTING STORM DRAIN EXISTING GAS EXISTING POWER EXISTING OVERHEAD POWER LINE TYPICAL EXISTING FIBER OPTIC EXISTING WATER EXISTING CONTOURS LEGEND 364 SP1 SUBMITTALNORTHNOTE:-EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THEENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BESTRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS.-ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OFBOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM.-UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED INTHE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES ASARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED.FILE: PROJECT NO: CAD: QUALITY ASSURANCE: DRAWING HISTORY DATE DESCRIPTION IMES ADDITION, PLAT C-41-D SITE & DIMENSION PLAN GALLATIN COUNTY FAIRGROUNDS DESIGN FOR SURFACE IMPROVEMENTS BOZEMAN, MTC3.4- BOZ_13005_04_SITE_PROD.DWG JAZ 01/22/20 INF SUBMITTAL 04/01/20 04/29/20 - - - - SP1 1ST SUBMITTAL SP1 2ND SUBMITTAL - - - - -- BOZ-13005.04 EXISTING TELEPHONEEXISTING SANITARY SEWEREXISTING STORM DRAINEXISTING GASEXISTING POWEREXISTING OVERHEAD POWER LINETYPICALEXISTING FIBER OPTICEXISTING WATEREXISTING CONTOURSLEGEND365 SP1 SUBMITTALNORTH FILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTIONIMES ADDITION, PLAT C-41-DGRADING & DRAINAGE PLANGALLATIN COUNTY FAIRGROUNDSDESIGN FOR SURFACE IMPROVEMENTSBOZEMAN, MTC4.1 -BOZ_13005_04_GRADING_PROD.DWGJAZ01/22/20INF SUBMITTAL04/01/2004/29/20----SP1 1ST SUBMITTALSP1 2ND SUBMITTAL------BOZ-13005.04EXISTING GRADE CONTOURS FINISH GRADE CONTOURS EXISTING TELEPHONE EXISTING SANITARY SEWER EXISTING STORM DRAIN EXISTING GAS EXISTING POWER EXISTING OVERHEAD POWER LINE TYPICAL EXISTING FIBER OPTIC EXISTING WATER LEGEND NOTE: -EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THE ENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BE STRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS. -ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OF BOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM. -UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED IN THE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES AS ARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED. 366 SP1 SUBMITTALNORTHNOTE:-EXISTING UNDERGROUND INSTALLATIONS & PRIVATE UTILITIES SHOWN ARE INDICATED ACCORDING TO THE BEST INFORMATION AVAILABLE TO THE ENGINEER. THEENGINEER DOES NOT GUARANTEE THE ACCURACY OF SUCH INFORMATION. SERVICE LINES (WATER, POWER, GAS, STORM, SEWER, TELEPHONE & TELEVISION) MAY NOT BESTRAIGHT LINES OR AS INDICATED ON THE PLANS. STATE LAW REQUIRES CONTRACTOR TO CALL ALL UTILITY COMPANIES BEFORE EXCAVATION FOR EXACT LOCATIONS.-ALL IMPROVEMENTS SHALL BE PERFORMED IN ACCORDANCE WITH MONTANA PUBLIC WORKS STANDARD SPECIFICATIONS 6TH EDITION, APRIL, 2010, AND THE CITY OFBOZEMAN STANDARD MODIFICATIONS, DATED MARCH 31, 2011, WITH ADDENDUM.-UNLESS OTHERWISE SPECIFIED, ALL CONSTRUCTION LAYOUT AND STAKING SHALL BE PERFORMED UNDER THE RESPONSIBLE CHARGE OF A LAND SURVEYOR LICENSED INTHE STATE WHERE THE PROJECT IS LOCATED AND BY A PARTY CHIEF OR ENGINEERING TECHNICIAN EXPERIENCED IN CONSTRUCTION LAYOUT AND STAKING TECHNIQUES ASARE REQUIRED BY THE SPECIFIC TYPE OF WORK BEING PERFORMED.FILE: PROJECT NO: CAD: QUALITY ASSURANCE: DRAWING HISTORY DATE DESCRIPTION IMES ADDITION, PLAT C-41-D GRADING & DRAINAGE PLAN GALLATIN COUNTY FAIRGROUNDS DESIGN FOR SURFACE IMPROVEMENTS BOZEMAN, MTC4.2- BOZ_13005_04_GRADING_PROD.DWG JAZ 01/22/20 INF SUBMITTAL 04/01/20 04/29/20 - - - - SP1 1ST SUBMITTAL SP1 2ND SUBMITTAL - - - - -- BOZ-13005.04 EXISTING GRADE CONTOURSFINISH GRADE CONTOURSEXISTING TELEPHONEEXISTING SANITARY SEWEREXISTING STORM DRAINEXISTING GASEXISTING POWEREXISTING OVERHEAD POWER LINETYPICALEXISTING FIBER OPTICEXISTING WATERLEGEND367 SP1 SUBMITTALFILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTIONIMES ADDITION, PLAT C-41-DDETAILSGALLATIN COUNTY FAIRGROUNDSDESIGN FOR SURFACE IMPROVEMENTSBOZEMAN, MTC5.0 -BOZ_13005_04_DETAILS_PROD.DWGJAZ01/22/20INF SUBMITTAL04/01/2004/29/20----SP1 1ST SUBMITTALSP1 2ND SUBMITTAL------BOZ-13005.04368 GALLATIN COUNTY FAIRGROUNDS SURFACE IMPROVEMENTS STORM DRAINAGE REPORT BOZEMAN, MONTANA CERTIFICATION I hereby state that this Final Drainage Report has been prepared by me or under my supervision and meets the standard of care and expertise which is usual and customary in this community of professional engineers. The analysis has been prepared utilizing procedures and practices specified by the City of Bozeman and within the standard accepted practices. ____________________________________________ ___________________________ Mike Russell, P.E. Date 04/01/2020 369 April 1, 2020 Project No. BOZ 13005.04 STORM DRAINAGE PLAN FOR GALLATIN COUNTY FAIRGROUNDS “SURFACE IMPROVEMENTS” PROJECT GALLATIN COUNTY FAIRGROUNDS 901 NORTH BLACK AVENUE BOZEMAN, MONTANA 59715 OVERVIEW NARRATIVE The purpose of this drainage plan is to present a summary of calculations to quantify the stormwater runoff for the Gallatin County Fairgrounds “Surface Improvements” project. All design criteria and calculations are in accordance with The City of Bozeman Design Standards and Specifications Policy, dated March 2004. The site stormwater improvements have been designed with the intent to meet the current City of Bozeman drainage regulations for the entire site to the extent feasible. The site is located south of Oak Street and north of Tamarack Street. The entire Gallatin County Fairgrounds lot is approximately 64.7 acres. The intent of this surface improvements project is to use an on-site stockpile of recycled asphalt pavement material to “clean up” the identified areas. Stormwater facilities proposed in the previous “Asphalt Pathways” project were sized conservatively, assuming the entire area upstream (to the south) could be improved to asphalt paving. Calculations from the previous “Asphalt Pathways” project are included in this submittal. The existing surfaces that are being improved (and project extents) primarily consist of compacted gravel surfacing. The proposed improvements consists of re-surfacing the compacted gravel surfaces with recycled asphalt pavement to clean up exhibit areas and other areas with higher pedestrian and vehicle traffic. The retention pond constructed with the ‘Asphalt Pathways’ project was sized to store and retain the 25-year design event runoff from both the pathways project and this surface improvements project. An additional gravel swale with a subsurface boulder pit constructed along the southern boundary will intercept runoff flowing from the south and address concerns of runoff that has historically drained off-site to the Oak Street R.O.W. 370 V:13005_04_2020-04-01_DRAINAGE REPORT 2 (04/01/20) JAZ/mr I. Design Approach The modified rational method was used to determine peak runoff rates and volumes. The rational formula provided in The City of Bozeman Standard Specifications and Policy was used to calculate the peak runoff rates on site, time of concentration, rainfall intensities, etc. To be conservative, we treated most watersheds as if they were predominately impervious cover, therefore we assumed a time of concentration of 5-minutes. For gravel surfaces, a runoff coefficient of 0.6 was assumed. For recycled asphalt pavement, a runoff coefficient of 0.8 was assumed. II. Proposed Watershed Descriptions For the following sections, please refer to Appendix A of this report, which graphically shows and labels the watersheds as well as the proposed drainage and conveyance facilities. The previous ‘Asphalt Pathways’ Storm Drainage Report has also been appended to this report for reference. No percolation rates have been included in these calculations to be conservative. West Grandstand Improvements The west grandstand improvements include re-surfacing the existing compacted gravel surface with recycled asphalt pavement. Increased runoff to the west of the grandstand will be directed towards the existing drainage swale located along the southern and western edge of the proposed improvements. The 10-year pre-developed site detention is 420 ft3, and the 10-year post-developed site detention is 560 ft3, which results in increased runoff of 140 ft3. The swale located along the southern and western edge of these improvements is approximately 450 L.F. by 4 feet wide by 1 foot deep and provides approximately 1,800 ft3 of runoff. Adequate storage is provided for the West Grandstand improvements. East Grandstand Improvements The east grandstand improvements include re-surfacing the existing compacted gravel surface with recycled asphalt pavement. Increased runoff to the east of the grandstand will be directed towards the existing drainage swale located along the eastern edge of the proposed improvements. This existing drainage swale drains to the existing retention pond that was constructed with the ‘Asphalt Pathways’ project. For the surface improvements, the 10-year pre-developed site detention is 267 ft3, and the 10-year post-developed site detention is 356 ft3, which results in increased runoff of 89 ft3. The swale located along the eastern edge of these improvements provides approximately 405 ft3 of runoff and the retention pond was conservatively sized to provide 11,662 ft3, which is 2,468 ft3 more than the required 9,194 ft3 (see attached ‘Asphalt Pathways’ storm drainage calculations for Watershed 2). Adequate storage is provided for the East Grandstand improvements. West RV Parking Improvements (Between 1st and 2nd Entrance) The west RV parking improvements include re-surfacing the existing compacted gravel surface with recycled asphalt pavement. Historically, runoff in this area sheet flows across the gravel 371 V:13005_04_2020-04-01_DRAINAGE REPORT 3 (04/01/20) JAZ/mr surface and will either infiltrate or evaporate. The 10-year pre-developed site detention is 365 ft3, and the 10-year post-developed site detention is 486 ft3, which results in increased runoff of 121 ft3. This additional runoff will sheet flow across an area equal to approximately 31,000 ft2. This results in a very nominal increase in water depth across this area, and this increased runoff will continue to sheet flow across the gravel surface and infiltrate or evaporate. East RV Parking Improvements (Between 3rd and 4th Entrance) The east RV parking improvements include re-surfacing the existing compacted gravel surface with recycled asphalt pavement. Historically, runoff in this area sheet flows across the gravel surface and will either infiltrate or evaporate. The 10-year pre-developed site detention is 268 ft3, and the 10-year post-developed site detention is 357 ft3, which results in increased runoff of 89 ft3. This additional runoff will sheet flow across the Tamarack Lot, which is an area equal to approximately 93,000 ft2. This results in a very nominal increase in water depth across this area, and this increased runoff will continue to sheet flow across the gravel surface and infiltrate/evaporate. Main Entrance ADA Parking Improvements The main entrance ADA parking improvements include re-surfacing the existing compacted gravel surface with virgin asphalt pavement. The 10-year pre-developed site detention is 169 ft3, and the 10-year post-developed site detention is 267 ft3, which results in increased runoff of 98 ft3. Historically, runoff in this area sheet flows into the landscaping/swale to the north and east of the parking area where the runoff infiltrates or evaporates. Increased runoff due to the improvements will continue to sheet flow into the landscaping to the north and infiltrate/evaporate. Exhibition Area The exhibition area improvements include re-surfacing the existing compacted gravel surface with recycled asphalt pavement. The previous ‘Asphalt Pathways’ project constructed a boulder pit that was sized assuming all of the area to the south would be paved with virgin asphalt. Runoff will be captured by a gravel swale and two standpipe area inlets connected by a 12-inch perforated storm drain pipe. See attached ‘Asphalt Pathways’ storm drainage calculations for Watershed 1B. The area located between Tamarack and the Exhibit building historically sheet flows across the gravel surface into the landscaping area to the northeast where it infiltrates/evaporates. This area between Tamarack and the Exhibit building is 13,085 ft2 and has a 10-year pre- developed site detention of 529 ft3. The post-developed site detention is 705 ft3, which results in increased runoff of 176 ft3. A proposed drywell will be installed in this area sized to account for the runoff increase. Post-development site detention assuming a full pave-out results in 838 ft3, so the drywell was sized conservatively to store 310 ft3 (838 ft3 – 529 ft3). No infiltration has been considered in these calculations. See Sheet C4.2 for the grading plan in this area, and see Sheet C5.0 for the drywell detail. 372 V:13005_04_2020-04-01_DRAINAGE REPORT 4 (04/01/20) JAZ/mr III. Water Quality The City of Bozeman Design Standards and Specifications Policy states the requirement to capture or reuse the runoff generated from the first 0.5 inches of rainfall from a 24-hour storm. We meet this requirement by retaining all storm runoff on site with no discharge into the City storm drain system. IV. Outlet Structures All runoff will be captured and retained/infiltrated on site. There are no outlet structures proposed for this project. V. Appendices Appendix A – Watershed Map Appendix B – Hydrology Calculations Appendix C – Surface Improvements O&M Plan Appendix D – ‘Asphalt Pathways’ Storm Drain Report w/ Attachments 373 V:13005_04_2020-04-01_DRAINAGE REPORT 5 (04/01/20) JAZ/mr Appendix A WATERSHED MAP 374 APRIL 202004/01/2020NEW PROPOSEDDRYWELL FOREXHIBITION AREAWEST RVPARKINGRUNOFFTO SHEETFLOW INTHIS AREAADA PARKINGRUNOFF SHEETFLOWS TO THENORTH INTO THEEX. LANDSCAPINGWATERSHED 1AWATERSHED 1BWATERSHED 2WATERSHED 3DIRECTION OFSURFACE FLOWPROPOSEDDRYWELLSEXISTINGDRYWELLSCONVEYANCESWALE 2BASIN 1CONVEYANCESWALEEX. GRAVELSWALE ANDBOULDER PITEXISTINGSWALERUNOFF FROMWEST GRANDSTANDSHEET FLOWS INTOEX. SWALEEXHIBITION AREARUNOFF SHEETFLOWS TO GRAVELSWALE/BOULDER PITRUNOFF FROM EASTGRANDSTANDSHEET FLOWS INTOEX. SWALE TORETENTION BASIN375 V:13005_04_2020-04-01_DRAINAGE REPORT 6 (04/01/20) JAZ/mr Appendix B HYDROLOGY CALCULATIONS 376 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 10386 0.238 0.6 1 0.60 0.60 0.143057851 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 10386 0.2384 0.1431 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.14 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 1.31 5 3.22 0.46 10 2.05 0.29 15 1.58 0.23 20 1.31 0.19 25 1.13 0.16 30 1.00 0.14 35 0.91 0.13 40 0.83 0.12 45 0.77 0.11 50 0.72 0.10 55 0.68 0.10 60 0.64 0.09 75 0.55 0.08 90 0.49 0.07 105 0.44 0.06 120 0.41 0.06 150 0.35 0.05 180 0.31 0.04 360 0.20 0.03 720 0.13 0.02 1440 0.08 420.10 ft3 0.46 (ft3/s) Gravel RATIONAL METHOD FOR RUNOFF CALCULATIONS WEST GRANDSTAND - PRE-IMPROVEMENT CONDITIONS Surface Type Totals = 0.6000 Cwd x Cf =0.60 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 78.64 0.00 78.64 138.13 0.00 138.13 176.05 0.00 176.05 202.90 0.00 202.90 224.39 0.00 224.39 242.62 0.00 242.62 258.60 0.00 258.60 272.94 0.00 272.94 286.00 0.00 286.00 298.03 0.00 298.03 309.23 0.00 309.23 319.72 0.00 319.72 329.61 0.00 329.61 356.38 0.00 356.38 379.86 0.00 379.86 400.92 0.00 400.92 420.10 0.00 420.10 454.23 0.00 454.23 484.16 0.00 484.16 617.09 0.00 617.09 786.52 0.00 786.52 1002.46 0.00 1002.46 = 377 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 10386 0.238 0.8 1 0.80 0.80 0.19 1 0.00 0.00 0.00 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 10386 0.2384 0.1907 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.19 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 1.75 5 3.22 0.61 10 2.05 0.39 15 1.58 0.30 20 1.31 0.25 25 1.13 0.22 30 1.00 0.19 35 0.91 0.17 40 0.83 0.16 45 0.77 0.15 50 0.72 0.14 55 0.68 0.13 60 0.64 0.12 75 0.55 0.11 90 0.49 0.09 105 0.44 0.08 120 0.41 0.08 150 0.35 0.07 180 0.31 0.06 360 0.20 0.04 720 0.13 0.02 1440 0.08 0.02 560.14 ft3 0.61 (ft3/s) 1048.69 0.00 1048.69 1336.62 0.00 1336.62 645.54 0.00 645.54 822.78 0.00 822.78 560.14 0.00 560.14 605.64 0.00 605.64 506.48 0.00 506.48 534.56 0.00 534.56 439.47 0.00 439.47 475.17 0.00 475.17 412.31 0.00 412.31 426.29 0.00 426.29 381.33 0.00 381.33 397.38 0.00 397.38 344.80 0.00 344.80 363.92 0.00 363.92 299.19 0.00 299.19 323.49 0.00 323.49 234.74 0.00 234.74 270.53 0.00 270.53 104.85 0.00 104.85 184.17 0.00 184.17 = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) = 0.8000 Cwd x Cf =0.80 Runoff Volume Discharge Volume Site Detention = Totals Recycled Asphalt Pavement RATIONAL METHOD FOR RUNOFF CALCULATIONS WEST GRANDSTAND - POST-IMPROVEMENT CONDITIONS Surface Type = 378 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 6600 0.152 0.6 1 0.60 0.60 0.090909091 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 6600 0.1515 0.0909 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.09 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 0.83 5 3.22 0.29 10 2.05 0.19 15 1.58 0.14 20 1.31 0.12 25 1.13 0.10 30 1.00 0.09 35 0.91 0.08 40 0.83 0.08 45 0.77 0.07 50 0.72 0.07 55 0.68 0.06 60 0.64 0.06 75 0.55 0.05 90 0.49 0.04 105 0.44 0.04 120 0.41 0.04 150 0.35 0.03 180 0.31 0.03 360 0.20 0.02 720 0.13 0.01 1440 0.08 266.96 ft3 0.29 (ft3/s) Gravel RATIONAL METHOD FOR RUNOFF CALCULATIONS EAST GRANDSTAND - PRE-IMPROVEMENT CONDITIONS Surface Type Totals = 0.6000 Cwd x Cf =0.60 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 49.97 0.00 49.97 87.78 0.00 87.78 111.88 0.00 111.88 128.93 0.00 128.93 142.59 0.00 142.59 154.18 0.00 154.18 164.33 0.00 164.33 173.44 0.00 173.44 181.74 0.00 181.74 189.39 0.00 189.39 196.51 0.00 196.51 203.17 0.00 203.17 209.45 0.00 209.45 226.47 0.00 226.47 241.39 0.00 241.39 254.77 0.00 254.77 266.96 0.00 266.96 288.65 0.00 288.65 307.67 0.00 307.67 392.14 0.00 392.14 499.81 0.00 499.81 637.04 0.00 637.04 = 379 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 6600 0.152 0.8 1 0.80 0.80 0.12 1 0.00 0.00 0.00 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 6600 0.1515 0.1212 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.12 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 1.11 5 3.22 0.39 10 2.05 0.25 15 1.58 0.19 20 1.31 0.16 25 1.13 0.14 30 1.00 0.12 35 0.91 0.11 40 0.83 0.10 45 0.77 0.09 50 0.72 0.09 55 0.68 0.08 60 0.64 0.08 75 0.55 0.07 90 0.49 0.06 105 0.44 0.05 120 0.41 0.05 150 0.35 0.04 180 0.31 0.04 360 0.20 0.02 720 0.13 0.02 1440 0.08 0.01 355.95 ft3 0.39 (ft3/s) Recycled Asphalt Pavement RATIONAL METHOD FOR RUNOFF CALCULATIONS EAST GRANDSTAND - POST-IMPROVEMENT CONDITIONS Surface Type Totals = 0.8000 Cwd x Cf =0.80 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 66.63 0.00 66.63 117.03 0.00 117.03 149.17 0.00 149.17 171.91 0.00 171.91 190.12 0.00 190.12 205.57 0.00 205.57 219.11 0.00 219.11 231.26 0.00 231.26 242.32 0.00 242.32 252.52 0.00 252.52 262.01 0.00 262.01 270.90 0.00 270.90 279.27 0.00 279.27 301.96 0.00 301.96 321.86 0.00 321.86 339.70 0.00 339.70 355.95 0.00 355.95 384.86 0.00 384.86 410.22 0.00 410.22 522.86 0.00 522.86 666.41 0.00 666.41 849.38 0.00 849.38 = 380 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 9019 0.207 0.6 1 0.60 0.60 0.1242 0 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 9019 0.2070 0.1242 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.12 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 1.14 5 3.22 0.40 10 2.05 0.25 15 1.58 0.20 20 1.31 0.16 25 1.13 0.14 30 1.00 0.12 35 0.91 0.11 40 0.83 0.10 45 0.77 0.10 50 0.72 0.09 55 0.68 0.08 60 0.64 0.08 75 0.55 0.07 90 0.49 0.06 105 0.44 0.06 120 0.41 0.05 150 0.35 0.04 180 0.31 0.04 360 0.20 0.02 720 0.13 0.02 1440 0.08 364.81 ft3 0.40 (ft3/s) Gravel RATIONAL METHOD FOR RUNOFF CALCULATIONS WEST RV PARKING - PRE-IMPROVEMENT CONDITIONS Surface Type Totals = 0.6000 Cwd x Cf =0.60 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 68.29 0.00 68.29 119.95 0.00 119.95 152.88 0.00 152.88 176.19 0.00 176.19 194.86 0.00 194.86 210.68 0.00 210.68 224.57 0.00 224.57 237.01 0.00 237.01 248.35 0.00 248.35 258.81 0.00 258.81 268.53 0.00 268.53 277.64 0.00 277.64 286.22 0.00 286.22 309.47 0.00 309.47 329.86 0.00 329.86 348.15 0.00 348.15 364.81 0.00 364.81 394.44 0.00 394.44 420.43 0.00 420.43 535.87 0.00 535.87 683.00 0.00 683.00 870.52 0.00 870.52 = 381 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 9019 0.207 0.8 1 0.80 0.80 0.166 1 0.00 0.00 0.000 1 0.00 0.00 0 9019 0.207 0.166 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.17 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 1.52 5 3.22 0.53 10 2.05 0.34 15 1.58 0.26 20 1.31 0.22 25 1.13 0.19 30 1.00 0.17 35 0.91 0.15 40 0.83 0.14 45 0.77 0.13 50 0.72 0.12 55 0.68 0.11 60 0.64 0.11 75 0.55 0.09 90 0.49 0.08 105 0.44 0.07 120 0.41 0.07 150 0.35 0.06 180 0.31 0.05 360 0.20 0.03 720 0.13 0.02 1440 0.08 0.01 486.41 ft3 0.34 (ft3/s) RATIONAL METHOD FOR RUNOFF CALCULATIONS WEST RV PARKING - POST-IMPROVEMENT CONDITIONS Surface Type Recycled Asphalt Pavement Totals = = 0.8000 Cwd x Cf =0.80 Runoff Volume Discharge Volume Site Detention = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 91.05 0.00 91.05 159.93 0.00 159.93 203.84 0.00 203.84 234.92 0.00 234.92 259.81 0.00 259.81 280.91 0.00 280.91 299.42 0.00 299.42 316.02 0.00 316.02 331.14 0.00 331.14 345.08 0.00 345.08 358.04 0.00 358.04 370.18 0.00 370.18 381.63 0.00 381.63 412.63 0.00 412.63 439.82 0.00 439.82 464.20 0.00 464.20 486.41 0.00 486.41 525.92 0.00 525.92 560.58 0.00 560.58 714.49 0.00 714.49 910.66 0.00 910.66 1160.69 0.00 1160.69 = 382 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 6624 0.152 0.6 1 0.60 0.60 0.091239669 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 1 0.00 0.00 0 6624 0.1521 0.0912 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.09 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 0.84 5 3.22 0.29 10 2.05 0.19 15 1.58 0.14 20 1.31 0.12 25 1.13 0.10 30 1.00 0.09 35 0.91 0.08 40 0.83 0.08 45 0.77 0.07 50 0.72 0.07 55 0.68 0.06 60 0.64 0.06 75 0.55 0.05 90 0.49 0.04 105 0.44 0.04 120 0.41 0.04 150 0.35 0.03 180 0.31 0.03 360 0.20 0.02 720 0.13 0.01 1440 0.08 267.93 ft3 0.29 (ft3/s) Gravel RATIONAL METHOD FOR RUNOFF CALCULATIONS EAST RV PARKING - PRE-IMPROVEMENT CONDITIONS Surface Type Totals = 0.6000 Cwd x Cf =0.60 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 50.15 0.00 50.15 88.10 0.00 88.10 112.28 0.00 112.28 129.40 0.00 129.40 143.11 0.00 143.11 154.74 0.00 154.74 164.93 0.00 164.93 174.08 0.00 174.08 182.40 0.00 182.40 190.08 0.00 190.08 197.22 0.00 197.22 203.91 0.00 203.91 210.22 0.00 210.22 227.29 0.00 227.29 242.27 0.00 242.27 255.70 0.00 255.70 267.93 0.00 267.93 289.70 0.00 289.70 308.79 0.00 308.79 393.57 0.00 393.57 501.63 0.00 501.63 639.35 0.00 639.35 = 383 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 6624 0.152 0.8 1 0.80 0.80 0.122 1 0.00 0.00 0.000 1 0.00 0.00 0.000 1 0.00 0.00 0.000 1 0.00 0.00 0 6624 0.152 0.122 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.12 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 1.11 5 3.22 0.39 10 2.05 0.25 15 1.58 0.19 20 1.31 0.16 25 1.13 0.14 30 1.00 0.12 35 0.91 0.11 40 0.83 0.10 45 0.77 0.09 50 0.72 0.09 55 0.68 0.08 60 0.64 0.08 75 0.55 0.07 90 0.49 0.06 105 0.44 0.05 120 0.41 0.05 150 0.35 0.04 180 0.31 0.04 360 0.20 0.02 720 0.13 0.02 1440 0.08 0.01 357.24 ft3 0.25 (ft3/s) 668.83 0.00 668.83 852.47 0.00 852.47 411.72 0.00 411.72 524.76 0.00 524.76 357.24 0.00 357.24 386.26 0.00 386.26 323.03 0.00 323.03 340.93 0.00 340.93 280.29 0.00 280.29 303.06 0.00 303.06 262.96 0.00 262.96 271.88 0.00 271.88 243.21 0.00 243.21 253.44 0.00 253.44 219.91 0.00 219.91 232.10 0.00 232.10 190.81 0.00 190.81 206.32 0.00 206.32 149.71 0.00 149.71 172.54 0.00 172.54 66.87 0.00 66.87 117.46 0.00 117.46 = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) = 0.8000 Cwd x Cf =0.80 Runoff Volume Discharge Volume Site Detention = Totals Recycled Asphalt Pavement RATIONAL METHOD FOR RUNOFF CALCULATIONS EAST RV PARKING - POST-IMPROVEMENT CONDITIONS Surface Type = 384 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 4172 0.096 0.6 1 0.60 0.60 0.057465565 0.000 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 4172 0.0958 0.0575 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.06 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 0.53 5 3.22 0.18 10 2.05 0.12 15 1.58 0.09 20 1.31 0.08 25 1.13 0.06 30 1.00 0.06 35 0.91 0.05 40 0.83 0.05 45 0.77 0.04 50 0.72 0.04 55 0.68 0.04 60 0.64 0.04 75 0.55 0.03 90 0.49 0.03 105 0.44 0.03 120 0.41 0.02 150 0.35 0.02 180 0.31 0.02 360 0.20 0.01 720 0.13 0.01 1440 0.08 168.75 ft3 0.18 (ft3/s) Gravel RATIONAL METHOD FOR RUNOFF CALCULATIONS ADA PARKING - PRE-IMPROVEMENT CONDITIONS Surface Type Totals = 0.6000 Cwd x Cf =0.60 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 31.59 0.00 31.59 55.49 0.00 55.49 70.72 0.00 70.72 81.50 0.00 81.50 90.14 0.00 90.14 97.46 0.00 97.46 103.88 0.00 103.88 109.64 0.00 109.64 114.88 0.00 114.88 119.72 0.00 119.72 124.22 0.00 124.22 128.43 0.00 128.43 132.40 0.00 132.40 143.16 0.00 143.16 152.59 0.00 152.59 161.05 0.00 161.05 168.75 0.00 168.75 182.46 0.00 182.46 194.48 0.00 194.48 247.88 0.00 247.88 315.94 0.00 315.94 402.68 0.00 402.68 = 385 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 4172 0.096 0.95 1 0.95 0.95 0.091 1 0.00 0.00 0.000 1 0.00 0.00 0.000 1 0.00 0.00 0.000 1 0.00 0.00 0 4172 0.096 0.091 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.09 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 0.83 5 3.22 0.29 10 2.05 0.19 15 1.58 0.14 20 1.31 0.12 25 1.13 0.10 30 1.00 0.09 35 0.91 0.08 40 0.83 0.08 45 0.77 0.07 50 0.72 0.07 55 0.68 0.06 60 0.64 0.06 75 0.55 0.05 90 0.49 0.04 105 0.44 0.04 120 0.41 0.04 150 0.35 0.03 180 0.31 0.03 360 0.20 0.02 720 0.13 0.01 1440 0.08 0.01 267.19 ft3 0.19 (ft3/s) Asphalt Pavement RATIONAL METHOD FOR RUNOFF CALCULATIONS ADA PARKING - POST-IMPROVEMENT CONDITIONS Surface Type Totals = 0.9500 Cwd x Cf =0.95 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 50.02 0.00 50.02 87.85 0.00 87.85 111.97 0.00 111.97 129.05 0.00 129.05 142.72 0.00 142.72 154.31 0.00 154.31 164.48 0.00 164.48 173.59 0.00 173.59 181.90 0.00 181.90 189.55 0.00 189.55 196.67 0.00 196.67 203.35 0.00 203.35 209.63 0.00 209.63 226.66 0.00 226.66 241.60 0.00 241.60 254.99 0.00 254.99 267.19 0.00 267.19 288.90 0.00 288.90 307.93 0.00 307.93 392.48 0.00 392.48 500.24 0.00 500.24 637.58 0.00 637.58 = 386 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 13085 0.300 0.6 1 0.60 0.60 0.18023416 0.000 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 13085 0.3004 0.1802 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.18 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 1.65 5 3.22 0.58 10 2.05 0.37 15 1.58 0.28 20 1.31 0.24 25 1.13 0.20 30 1.00 0.18 35 0.91 0.16 40 0.83 0.15 45 0.77 0.14 50 0.72 0.13 55 0.68 0.12 60 0.64 0.12 75 0.55 0.10 90 0.49 0.09 105 0.44 0.08 120 0.41 0.07 150 0.35 0.06 180 0.31 0.06 360 0.20 0.04 720 0.13 0.02 1440 0.08 529.27 ft3 0.58 (ft3/s) Gravel RATIONAL METHOD FOR RUNOFF CALCULATIONS EXHIBITION AREA - PRE-IMPROVEMENT CONDITIONS Surface Type Totals = 0.6000 Cwd x Cf =0.60 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 99.08 0.00 99.08 174.02 0.00 174.02 221.80 0.00 221.80 255.62 0.00 255.62 282.70 0.00 282.70 305.66 0.00 305.66 325.81 0.00 325.81 343.87 0.00 343.87 360.32 0.00 360.32 375.48 0.00 375.48 389.59 0.00 389.59 402.80 0.00 402.80 415.26 0.00 415.26 448.99 0.00 448.99 478.58 0.00 478.58 505.11 0.00 505.11 529.27 0.00 529.27 572.27 0.00 572.27 609.97 0.00 609.97 777.45 0.00 777.45 990.91 0.00 990.91 1262.97 0.00 1262.97 = 387 Project: Gallatin County Surface Improvements Project #: BOZ_13005.04 Date: 4/1/2020 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 13085 0.300 0.95 1 0.95 0.95 0.285 1 0.00 0.00 0.000 1 0.00 0.00 0.000 1 0.00 0.00 0.000 1 0.00 0.00 0 13085 0.300 0.285 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.29 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 2.61 5 3.22 0.92 10 2.05 0.59 15 1.58 0.45 20 1.31 0.37 25 1.13 0.32 30 1.00 0.29 35 0.91 0.26 40 0.83 0.24 45 0.77 0.22 50 0.72 0.21 55 0.68 0.19 60 0.64 0.18 75 0.55 0.16 90 0.49 0.14 105 0.44 0.13 120 0.41 0.12 150 0.35 0.10 180 0.31 0.09 360 0.20 0.06 720 0.13 0.04 1440 0.08 0.02 838.02 ft3 0.59 (ft3/s) Asphalt Pavement RATIONAL METHOD FOR RUNOFF CALCULATIONS EXHIBITION AREA - POST-IMPROVEMENT CONDITIONS Surface Type Totals = 0.9500 Cwd x Cf =0.95 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 156.87 0.00 156.87 275.54 0.00 275.54 351.19 0.00 351.19 404.74 0.00 404.74 447.61 0.00 447.61 483.97 0.00 483.97 515.86 0.00 515.86 544.46 0.00 544.46 570.51 0.00 570.51 594.52 0.00 594.52 616.85 0.00 616.85 637.77 0.00 637.77 657.49 0.00 657.49 710.90 0.00 710.90 757.75 0.00 757.75 799.75 0.00 799.75 838.02 0.00 838.02 906.09 0.00 906.09 965.79 0.00 965.79 1230.96 0.00 1230.96 1568.94 0.00 1568.94 1999.70 0.00 1999.70 = 388 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 7/9/2018 TABLE I-1: Runoff Coefficients for Use in the Rational Method LAND USE RUNOFF COEFFICIENTS, C Open Land 0.2 Low to Medium Density Residential 0.35 Dense Residential 0.5 Commercial Neighborhood 0.6 Commercial Downtown 0.8 Industrial 0.8 389 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 7/9/2018 Design Standards and Specifications Policy City of Bozeman, March 2004 as Amended RAINFALL INTENSITY-DURATION CURVES (Figures I-2, I-3) Time 2 5 10 25 50 100 (min)(in/hr)(in/hr)(in/hr)(in/hr)(in/hr)(in/hr) 1 4.20 7.15 9.16 10.72 13.72 15.69 5 1.60 2.55 3.22 3.83 4.74 5.34 10 1.05 1.64 2.05 2.46 3.00 3.35 15 0.83 1.26 1.58 1.89 2.30 2.56 20 0.70 1.05 1.31 1.58 1.90 2.11 25 0.61 0.91 1.13 1.37 1.64 1.82 30 0.55 0.81 1.00 1.22 1.45 1.61 35 0.50 0.73 0.91 1.10 1.31 1.45 40 0.46 0.67 0.83 1.01 1.20 1.33 45 0.43 0.63 0.77 0.94 1.11 1.22 50 0.40 0.58 0.72 0.88 1.04 1.14 55 0.38 0.55 0.68 0.82 0.97 1.07 60 0.36 0.52 0.64 0.78 0.92 1.01 75 0.31 0.45 0.55 0.68 0.79 0.87 90 0.28 0.40 0.49 0.60 0.70 0.77 105 0.26 0.36 0.44 0.55 0.64 0.69 120 0.24 0.33 0.41 0.50 0.58 0.63 150 0.21 0.29 0.35 0.43 0.50 0.55 180 0.19 0.26 0.31 0.39 0.45 0.48 360 0.12 0.17 0.20 0.25 0.28 0.30 720 0.08 0.11 0.13 0.16 0.18 0.19 1440 0.05 0.07 0.08 0.10 0.11 0.12 Storm Recurrence Interval 390 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 7/9/2018 Design Standards and Specifications Policy City of Bozeman, March 2004 as Amended Zoning District/Design Storm Requirement Zoning Type Design Rainfall Frequency Open Land 2-year Residential 10-year Commercial 10-year (p. 28, Table I-3) 391 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 7/9/2018 STORMWATER MANAGEMENT MANUAL TABLE 2-5 FREQUENCY FACTORS FOR THE RATIONAL FORMULA Recurrence Interval Adjustment Factor (Years)Cf 2 1.00 5 1.00 10 1.00 25 1.10 50 1.20 100 1.25 * C X Cf should not exceed 1.0 392 V:13005_04_2020-04-01_DRAINAGE REPORT 7 (04/01/20) JAZ/mr Appendix C SURFACE IMPROVEMENTS O&M PLAN 393 April 1, 2020 Project No. BOZ 13005.03 STORM DRAINAGE FACILITY MAINTENANCE PLAN FOR GALLATIN COUNTY FAIRGROUNDS SURFACE IMPROVEMENTS BOZEMAN, MONTANA OVERVIEW NARRATIVE The purpose of this maintenance plan is to outline the necessary details related to ownership, responsibility and cleaning schedule for the storm drainage facilities for the Gallatin County Fairgrounds. This plan has been completed in accordance with The City of Bozeman Design Standards and Specifications Policy, dated March 2004. The site stormwater improvements have been designed with the intent to meet the current City of Bozeman drainage regulations for the entire site to the extent feasible. Specific site information and criteria are described below: I. Ownership of Facilities Gallatin County Fairgrounds Gallatin County Fairgrounds will own all stormwater facilities which includes the dry wells, conveyance ditches and the detention basin. II. Inspection Thresholds for Cleaning Basin If the average depth of sediment exceeds 6 inches, clean basin Conveyance Ditches If the average depth of sediment exceeds 2 inches, clean entire ditch Dry Wells If sediment in sump exceeds 5 inches or grate is more than 25% clogged with debris, clean grate and/or structure 394 V:13005_04_O&M 2 (04/01/20) JAZ/mr III. Cleaning Basin Excavate or dig sediment out of basin and dispose of excess sediment Conveyance Ditches Excavate or dig sediment out of basin and dispose of excess sediment Dry Wells To clean grate of structure, remove and dispose of debris clogging the grate. To clean structure, use catch basin vacuum to remove sediment and debris IV. Schedule Basin Inspection: Every 6 months Clean Basin: Every 5 years or as needed based on inspection Conveyance Ditches Inspection: Every 6 months Clean Ditches: Every 5 years or as needed based on inspection Dry Wells Inspection: Every 6 months Vacuum Drywells: Every 5 years or as needed based on inspection V. Responsible Party Gallatin County Fairgrounds The Gallatin County Fairgrounds will be responsible for the inspection and maintenance of all stormwater facilities located within the project limits I agree to the above operation, maintenance and replacement schedule detailed above. Signature: __________________________________________ Gallatin County Fairgrounds Representative 395 Checklist continued on next page INSPECTOR’S NAME:DATE:NAME & ADDRESS OF STORMWATERFACILITY:GENERAL OBSERVATIONS (IS WATERFLOWING?):WEATHER:Checked? (Y/N)Maintenance Needed? (Y/N)Observations and Remarks Look for debris, trash and sediment blocking catch basin grate. If found, remove. Replace grate if damaged.Inspect filter if installed. Change if torn or clogged.Look for sediment and trash in catch basin sump. Clean out if sediment fills 60% of the sump or comes within 6” of a pipe.Look for damage or cracks to frame, grate, basin walls or bottom. If found, repair or replace.Check integrity of ladder rungs, cleanout gate, and orifice plate. If bent or obstructed, take appropriate action. Check for undercutting, scouring, and slumping. If found, repair or maintain.Remove all trash and loose sediment. Remove sediment if it will impede water flow or clog downstream structures.Remove vegetation that impedes water movement. Remove vegetation over 9” in height, and all trees and shrubs impeding flow.Repair check dams as necessary.Remove any dumped yard waste.In ditches and swales, check for integrity of grass, check dams, inlets, and outlets. Remove shrubs and trees. CATCH BASINS AND INLETS CONVEYANCES Stormwater System Inspection Checklist G-6 | Page 396 Checked? (Y/N)Maintenance Needed? (Y/N)Observations and Remarks Inlets and outlets: remove vegetation and debris. Fix erosion and scouring. Fix cause of sediment found below outlet.Remove vegetation and debris from trash rack.Add rock to energy dissipater if missing.If necessary, repair rock on spillway. Remove trees, shrubs, and vegetation over 4”. If piping or erosion is visible, consult engineer. Check for slumping or sloughing of walls. If over 4” of slumping, consult with an engineer. Fix any erosion or scouring. If leaks, piping or soft spots are found, consult with an engineer.If liner visible on bottom, check for holes or replace.Clean any oil sheen from water with oil-absorbent pads or vactor truckChecksediment depth near inlet.If more than one footexists,or there is build upnear inlet,the pond needs to becleaned. On the pond walls, mow grass to 4 – 9”. Remove clippings. Reseed bare areas.On pond surface, emergent vegetation over 50% of the area indicates sediment removal needed.On pond bottom, remove tree seedlings.Around the pond,remove trees and shrubs that shadesidewallgrassorthatmighthaveproblemrootsnearpipes and structures.Remove invasive and poisonous plants.Remove algae if over 10% of surface.Check integrity of access ramp; ensure stable and clear for heavy equipment.Check integrity and operation of all fences, gates, and locks. Repair as needed for ease of access.Remove rodents and insects if evidence found.Remove vegetation on fences. POND COMPONENTS OF THE POND ACCESS AND SAFETY VEGETATION G-7 | Page 397 POST CONSTRUCTION BMP INSPECTION CHECKLIST MonthlySchedule/Frequency AnnuallyAnnually Inspect pond area, sidewalls, and shoreline for erosion, settlement, and rodent damage Inspect exterior of catch basins AnnuallyAnnuallyAnnually QuarterlyMonthly and after storm events Quarterly and after storm eventsQuarterly, and after storm eventsQuarterly and after storm events Quarterly Inspect ditches, check dams, and all visible pipes and culverts for trash, obstructions and other problems Inspect bioswales for vegetation cover and bare areasInspect fences, gates and locks Quarterly Prepared by RESources for Sustainable Communities for the Birch Bay Watershed & Aquatic Resources Management (BBWARM) District. This project was been funded wholly or in part by the U.S. Environmental Protection Agency under assistance agreement WS-96073401 to Whatcom County. The content of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendations for use. Inspect pond area for oil sheens or trash Inspect access ramps for ease of heavy equipment access Inspect inside catch basins, including flow restrictor/orifice plate Inspect spillway for vegetation overgrowth and ease of heavy equipment access Inspect interior of catch basins for debris and sediment Pond area sediment accumulation (pond bottom) Inspect pond area for undesirable or poisonous vegetation and noxious weedsInspect water levels in the pondInspect trash racks, debris barriers, and energy dissipaters Inspect inlets and outlets for trash, obstructions, and vegetation Activity Semi-annually, during growing seasonAfter storm events G-5 | Page 398 V:13005_04_2020-04-01_DRAINAGE REPORT 8 (04/01/20) JAZ/mr Appendix D ‘ASPHALT PATHWAYS’ STORM DRAINAGE REPORT W/ ATTACHMENTS 399 December 17, 2019 Project No. BOZ 13005.03 STORM DRAINAGE PLAN FOR GALLATIN COUNTY FAIRGROUNDS “ASPHALT PATHWAYS” PROJECT GALLATIN COUNTY FAIRGROUNDS 901 NORTH BLACK AVENUE BOZEMAN, MONTANA 59715 OVERVIEW NARRATIVE The purpose of this drainage plan is to present a summary of calculations to quantify the stormwater runoff for the Gallatin County Fairgrounds “Asphalt Pathways” improvements project. All design criteria and calculations are in accordance with The City of Bozeman Design Standards and Specifications Policy, dated March 2004. The site stormwater improvements have been designed with the intent to meet the current City of Bozeman drainage regulations for the entire site to the extent feasible. The site is located south of Oak Street and north of Tamarack Street. The entire Gallatin County Fairgrounds lot is approximately 64.7 acres. However, the project will disturb only ~2.74 acres of the site and increase the impervious area by ~0.95 acres. The intent of the stormwater design is to mitigate runoff from the asphalt pathways improvement project limits through a small series of dry wells and the proposed retention pond. All stormwater runoff generated from this project will be retained/infiltrated on site. The existing surfaces that are being improved (and project extents) primarily consist of compacted gravel surfacing. The proposed development consists of an asphalt access pathway to assist with internal circulation of pedestrian and vehicular traffic. The retention pond will be sized to store and retain the 25-year design event runoff from the proposed surface improvements. An additional gravel swale with a subsurface boulder pit has been added to this project along the southern boundary to intercept runoff flowing from the south and addressing concerns of runoff that has historically drained off-site to the Oak Street R.O.W. 400 V:13005_03_2019-12-17_Storm_Drainage_Plan 2 (12/17/19) MTR I. Design Approach The modified rational method was used to determine peak runoff rates and volumes. The rational formula provided in The City of Bozeman Standard Specifications and Policy was used to calculate the peak runoff rates on site, time of concentration, rainfall intensities, etc. To be conservative, we treated most watersheds as if they were predominately impervious cover, therefore we assumed a time of concentration of 5-minutes. For gravel surfaces, a runoff coefficient of 0.6 was assumed. II. Proposed Watershed Descriptions For the following sections, please refer to Appendix A of this report, which graphically shows and labels the watersheds as well as the proposed drainage and conveyance facilities. Watershed 1A flows into existing dry wells located south of the existing hockey rink building. These dry wells are called out and identified within Appendix A. Excess runoff that cannot enter the existing dry wells will overtop into Conveyance Swale 1 (called out in Appendix A) and outfall into Watershed 2. A detail for the existing drywells from the As-Built construction drawings dated 12/15/2014 is attached to this report. Based on the dimensions shown in the detail, we have calculated that each of the four dry wells located on site provide approximately 469 ft3 of storage, or a total of 1,876 ft3. The required 25-year, 2-hour storm storage for Watershed 1A was calculated to be 1,493 ft3 using a conservative percolation rate of 6.8 in/hr, which is the minimum rate for poorly graded sandy gravels according to USCS Soil Classifications. Watershed 1B runoff will be intercepted by a proposed gravel swale (shown in Appendix A), located along the southern edge of asphalt of the new paved pathway. A new proposed boulder pit will be installed below the proposed swale along with two Type IV area inlets and 12-inch perforated storm drain pipe. The proposed boulder pit was sized with the assumption that further paving improvements will be constructed. Based on the Watershed 1B limits shown in Appendix A and the breakdown of future pervious and impervious areas, the required storage for this watershed is 6,932 ft3. The boulder pit was sized to provide 8,113 ft3, to be conservative and to account for future improvements of changing gravel to pavement upstream of the gravel swale. Watershed 2 is conveyed to the north Conveyance Swale 1 and Conveyance Swale 2, into Basin 1 (a newly proposed retention pond). The conveyance swales have the capacity to convey the 25-year storm event to Basin 1. The 25-year design event requires a storage of 9,194 cubic feet, and Basin 1 has the capacity to retain 11,662 cubic feet to store runoff, to be conservative. Additionally, Conveyance Swale 2 directly south of Basin 1 provides 405 cubic feet of storage. Sanderson Stewart conducted percolation/infiltration rates at the location of the proposed Basin 1 retention pond after 24-hours of saturation of the soils resulting in a percolation rate of 1.38 inches per hour. Percolation rates were measured between approximately three to four feet in depth in soils that could be classified as lean clays with sand. The proposed retention pond shows a final depth of approximately of six to seven feet in depth below existing grade. Historical exploratory bores ~600’ south 401 V:13005_03_2019-12-17_Storm_Drainage_Plan 3 (12/17/19) MTR indicated a “poorly-graded gravel with sand and clay,” lens of soils at depths ranging from 2- 3’ at the shallowest and 10’ at the deepest (where test pits were not excavated deeper.) (Geotechnical Report completed by TD&H Engineering in October 2012 created for the New Ice Hockey Pavilion Expansion project, See Appendix E.) In the event that these poorly-graded gravels are exposed during excavation, the pond should not need to be excavated any deeper. A note on Sheet C4.2 indicates that the contractor shall inform the Engineer of the depth of the existing gravel layer. Additional percolation through the “poorly-graded gravel with sand and clay” was accounted for with a conservative rate of 6.8 in/hr as the proposed depth of the pond will expose approximately 1,454 ft2 of that gravel lens to provide a larger area of percolation. Watershed 3 sheet flows into two new dry wells which will capture and retain runoff from minor storm events. Each drywell provides approximately 400 ft3 of storage, for a total of 800 ft3. During larger storm events runoff will pond over the dry wells and overtop into the adjacent fairground area. Excess runoff from the most easterly dry well may eventually drain to Basin 1 but will first experience percolation into surrounding soils as it has, historically. Excess runoff from the western dry well will drain into the adjacent existing swale to the west shown in Appendix A. This existing swale is approximately 400 feet long, 3-feet wide, and 1 foot deep. This swale will provide an additional 1,200 ft3 of storage. The calculations for Watershed 3 show a required storage of 1,268 ft3, so adequate storage is provided including the dry wells and drainage swale, not counting for percolation. The underlying soils that the dry wells and basin will tie into are poorly graded gravel with sand and clay based on the Geotechnical Report completed by TD&H Engineering in October 2012 created for the New Ice Hockey Pavilion Expansion project. Percolation through this “poorly-graded gravel with sand and clay” lens was accounted for with a conservative rate of 6.8 in/hr. In all, Watershed 3 has sufficient storage and is conservatively designed to retain the design storm event. III. Proposed Storage and Conveyance Facilities Basin 1 Basin 1 is located to the north of the project limits within an existing drainage swale designed to convey runoff from the existing gravel road. A new, larger swale (Conveyance Swale 2) will be constructed to convey runoff to the new basin. The basin will be constructed in line with the existing swale and any excess runoff from the basin will overtop the north edge of the basin into the existing swale. The basin is designed to have 4:1 side slopes and a maximum water depth of 1.5 feet. Infiltration was considered as part of the design based on the underlying soil layers shown in the Geotechnical Report bore logs. The stage storage volume calculations for the proposed basin are attached to this report. Basin 1 and Conveyance Swale 2 will be seeded in order to limit the potential for erosion. Conveyance Swale 1 402 V:13005_03_2019-12-17_Storm_Drainage_Plan 4 (12/17/19) MTR As mentioned above, Conveyance Swale 1 is used to convey excess runoff from Watershed 1 to Watershed 2. The 25-year, 5-minute peak flow from Watershed 1 is 4.57 cfs and Conveyance Swale 1 has the capacity to convey 5.66 cfs. The maximum velocity through the channel is 1.06 ft/s. The channel will be cut into the existing gravels on site. The swale will be seeded for grass to prevent any erosion, but the low velocity rate should help minimize the potential for erosion. The Bentley Flowmaster swale capacity calculations are included in the appendix. Conveyance Swale 2 As mentioned above, Conveyance Swale 2 is used to convey excess runoff from Watershed 1 and 2. The 25-year, 5-minute peak flow from both watersheds is 8.07 cfs and Conveyance Swale 2 has the capacity to convey 8.14 cfs. The maximum velocity through the channel is 2.83 ft/s. The channel will be cut into the existing gravels on site. The swale will be seeded for grass to prevent any erosion, but the low velocity rate should help minimize the potential for erosion. The Bentley Flowmaster swale capacity calculations are included in the appendix. Dry Wells The new drywells on site are designed to capture runoff for minor storms and allow larger storms to pond up over the dry well and eventually infiltrate through the dry wells perforations. Any excess runoff will overtop into the fairgrounds area, then eventually into Basin 1 (to the east) or to the existing drainage swale (to the west). IV. Water Quality The City of Bozeman Design Standards and Specifications Policy states the requirement to capture or reuse the runoff generated from the first 0.5 inches of rainfall from a 24-hour storm. We meet this requirement by retaining all storm runoff on site with no discharge into the City storm drain system. V. Outlet Structures All runoff will be captured and retained/infiltrated on site. There are no outlet structures proposed for this project. 403 V:13005_03_2019-12-13_Storm_Drainage_Plan 6 (12/13/19) MTR Appendix A WATERSHED MAP 404 WATERSHED 1AWATERSHED 1BWATERSHED 2WATERSHED 3DIRECTION OFSURFACE FLOWPROPOSEDDRYWELLSEXISTINGDRYWELLSCONVEYANCESWALE 2BASIN 1CONVEYANCESWALE 1NEWPROPOSEDGRAVELSWALEEXISTING SWALE405 V:13005_03_2019-12-13_Storm_Drainage_Plan 7 (12/13/19) MTR Appendix B HYDROLOGY CALCULATIONS 406 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 12/13/2019 Design Storm Frequency =25 years Area of perc (ft^2)Perc rate (in/hr) Perc rate (ft/sec) 974 6.80 0.0001574 Discharge Rate, d =0.15 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 15529 0.356 0.8 1.1 0.88 0.88 0.314 16965 0.389 0.95 1.1 1.05 1.00 0.389 0 1.1 0.00 0.00 0 32494 0.746 0.703 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.72 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 10.72 7.72 5 3.83 2.76 10 2.46 1.77 15 1.89 1.37 20 1.58 1.14 25 1.37 0.98 30 1.22 0.88 35 1.10 0.79 40 1.01 0.73 45 0.94 0.68 50 0.88 0.63 55 0.82 0.59 60 0.78 0.56 75 0.68 0.49 90 0.60 0.43 105 0.55 0.39 120 0.50 0.36 150 0.43 0.31 180 0.39 0.28 360 0.25 0.18 720 0.16 0.11 1440 0.10 0.07 1,493.46 ft3 1.77 (ft3/s) RATIONAL METHOD FOR RUNOFF CALCULATIONS Watershed 1A Peak Flows Surface Type Gravel Asphalt/Concrete/Roof Totals = = 0.8783 Cwd x Cf =0.97 Runoff Volume Discharge Volume Site Detention = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 463.47 9.20 454.27 827.27 45.99 781.28 1061.75 91.99 969.76 1228.61 137.98 1090.63 1362.67 183.98 1178.69 1476.66 229.97 1246.68 1576.83 275.97 1300.86 1666.81 321.96 1344.85 1748.89 367.96 1380.93 1824.64 413.95 1410.69 1895.18 459.94 1435.23 1961.33 505.94 1455.39 2023.74 551.93 1471.81 2193.02 689.92 1503.10 2341.79 827.90 1513.89 2475.42 965.88 1509.54 2597.32 1103.87 1493.46 2814.58 1379.83 1434.75 3005.51 1655.80 1349.71 3857.35 3311.60 545.75 4950.63 6623.20 ----- 6353.77 13246.40 ----- = 407 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 12/13/2019 Design Storm Frequency =25 years Area of perc (ft^2)Perc rate (in/hr) Perc rate (ft/sec) 5337.5 6.80 0.0001574 Discharge Rate, d =0.84 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 32968 0.757 0.15 1.1 0.17 0.17 0.125 18260 0.419 0.8 1.1 0.88 0.88 0.369 37685 0.865 0.95 1.1 1.05 1.00 0.865 91878 2.109 0.95 1.1 1.05 1.00 2.109 0 1.1 0.00 0.00 0 180791 4.150 3.468 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =3.60 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 10.72 38.61 5 3.83 13.78 10 2.46 8.84 15 1.89 6.82 20 1.58 5.68 25 1.37 4.92 30 1.22 4.38 35 1.10 3.97 40 1.01 3.64 45 0.94 3.38 50 0.88 3.16 55 0.82 2.97 60 0.78 2.81 75 0.68 2.44 90 0.60 2.17 105 0.55 1.96 120 0.50 1.80 150 0.43 1.56 180 0.39 1.39 360 0.25 0.89 720 0.16 0.57 1440 0.10 0.37 6,931.88 ft3 8.84 (ft3/s) 24742.53 36295.00 ----- 31755.20 72590.00 ----- 15021.12 9073.75 5947.37 19278.50 18147.50 1131.00 12981.04 6049.17 6931.88 14066.86 7561.46 6505.40 11703.93 4536.88 7167.05 12371.79 5293.02 7078.77 10114.37 3024.58 7089.79 10960.40 3780.73 7179.67 9471.82 2520.49 6951.34 9802.46 2772.53 7029.92 8740.69 2016.39 6724.31 9119.29 2268.44 6850.85 7880.76 1512.29 6368.47 8330.46 1764.34 6566.12 6810.44 1008.19 5802.25 7380.11 1260.24 6119.87 5306.45 504.10 4802.36 6140.41 756.15 5384.26 2316.35 50.41 2265.94 4134.60 252.05 3882.55 = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) = 0.7890 Cwd x Cf =0.87 Runoff Volume Discharge Volume Site Detention = Gravel Concrete/Roof Asphalt Pavement Totals Landscape RATIONAL METHOD FOR RUNOFF CALCULATIONS Watershed 1B Peak Flows Surface Type = 408 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 12/13/2019 Design Storm Frequency =25 years Area of perc (ft^2)Perc rate (in/hr) Perc rate (ft/sec) Percolation Rate (GRAVEL), d =0.23 cfs 1454 6.80 0.0001574 Percolation Rate (SSC), d =0.14 cfs 4329 1.38 3.194E-05 Percolation Rate (Total), d =0.37 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 116649 2.678 0.9 1.1 0.99 0.99 2.65 41823 0.960 0.6 1.1 0.66 0.66 0.63 0 1.1 0.00 0.00 0 0 1.1 0.00 0.00 0 0 1.1 0.00 0.00 0 158472 3.6380 3.2848 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =3.28 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 10.72 35.21 5 3.83 12.57 10 2.46 8.07 15 1.89 6.22 20 1.58 5.18 25 1.37 4.49 30 1.22 3.99 35 1.10 3.62 40 1.01 3.32 45 0.94 3.08 50 0.88 2.88 55 0.82 2.71 60 0.78 2.56 75 0.68 2.22 90 0.60 1.98 105 0.55 1.79 120 0.50 1.64 150 0.43 1.43 180 0.39 1.27 360 0.25 0.81 720 0.16 0.52 1440 0.10 0.34 9,194.41 ft3 8.07 (ft3/s) 22563.72 15861.22 6702.50 28958.86 31722.44 ----- 13698.38 3965.31 9733.07 17580.85 7930.61 9650.24 11837.94 2643.54 9194.41 12828.14 3304.42 9523.72 10673.29 1982.65 8690.64 11282.34 2313.09 8969.24 9223.71 1321.77 7901.94 9995.24 1652.21 8343.03 8637.74 1101.47 7536.27 8939.26 1211.62 7727.64 7971.00 881.18 7089.82 8316.25 991.33 7324.92 7186.78 660.88 6525.90 7596.88 771.03 6825.85 6210.72 440.59 5770.13 6730.22 550.74 6179.49 4839.17 220.29 4618.88 5599.69 330.44 5269.25 2112.37 22.03 2090.35 3770.51 110.15 3660.36 = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) = 0.8208 Cwd x Cf =0.90 Runoff Volume Percolation/Infiltration Site Detention = Gravel Totals Impervious RATIONAL METHOD FOR RUNOFF CALCULATIONS Watershed 2 Peak Flows Surface Type = 409 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 12/13/2019 Design Storm Frequency =25 years Area of perc (ft^2)Perc rate (in/hr) Perc rate (ft/sec) Discharge Rate, d =0.16 cfs 1000 6.80 0.0001574 Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 11123 0.255 0.9 1.1 0.99 0.99 0.25 27298 0.627 0.6 1.1 0.66 0.66 0.41 0 1.1 0.00 0.00 0 0 1.1 0.00 0.00 0 0 1.1 0.00 0.00 0 38421 0.8820 0.6664 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.67 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 10.72 7.14 5 3.83 2.55 10 2.46 1.64 15 1.89 1.26 20 1.58 1.05 25 1.37 0.91 30 1.22 0.81 35 1.10 0.73 40 1.01 0.67 45 0.94 0.62 50 0.88 0.58 55 0.82 0.55 60 0.78 0.52 75 0.68 0.45 90 0.60 0.40 105 0.55 0.36 120 0.50 0.33 150 0.43 0.29 180 0.39 0.26 360 0.25 0.17 720 0.16 0.11 1440 0.10 0.07 1,268.28 ft3 2.55 (ft3/s) 4577.61 6800.00 ----- 5875.02 13600.00 ----- 2779.05 1700.00 1079.05 3566.71 3400.00 166.71 2401.62 1133.33 1268.28 2602.50 1416.67 1185.84 2165.34 850.00 1315.34 2288.90 991.67 1297.23 1871.26 566.67 1304.59 2027.78 708.33 1319.45 1752.38 472.22 1280.16 1813.55 519.44 1294.10 1617.11 377.78 1239.33 1687.16 425.00 1262.16 1458.02 283.33 1174.68 1541.21 330.56 1210.66 1260.00 188.89 1071.11 1365.39 236.11 1129.28 981.74 94.44 887.30 1136.03 141.67 994.37 428.55 9.44 419.10 764.94 47.22 717.72 = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) = 0.6869 Cwd x Cf =0.76 Runoff Volume Discharge Volume Site Detention = Gravel Totals Impervious RATIONAL METHOD FOR RUNOFF CALCULATIONS Watershed 3 Peak Flows Surface Type = 410 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 12/13/2019 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 41415 0.951 0.6 1 0.60 0.60 0.570454545 0.000 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 41415 0.9508 0.5705 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.57 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 5.23 5 3.22 1.84 10 2.05 1.17 15 1.58 0.90 20 1.31 0.75 25 1.13 0.64 30 1.00 0.57 35 0.91 0.52 40 0.83 0.48 45 0.77 0.44 50 0.72 0.41 55 0.68 0.39 60 0.64 0.37 75 0.55 0.32 90 0.49 0.28 105 0.44 0.25 120 0.41 0.23 150 0.35 0.20 180 0.31 0.18 360 0.20 0.11 720 0.13 0.07 1440 0.08 1,675.19 ft3 1.84 (ft3/s) Gravel RATIONAL METHOD FOR RUNOFF CALCULATIONS Pre-Project Runoff Volume Surface Type Totals = 0.6000 Cwd x Cf =0.60 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 313.58 0.00 313.58 550.80 0.00 550.80 702.02 0.00 702.02 809.06 0.00 809.06 894.77 0.00 894.77 967.45 0.00 967.45 1031.20 0.00 1031.20 1088.36 0.00 1088.36 1140.44 0.00 1140.44 1188.43 0.00 1188.43 1233.08 0.00 1233.08 1274.90 0.00 1274.90 1314.33 0.00 1314.33 1421.09 0.00 1421.09 1514.73 0.00 1514.73 1598.70 0.00 1598.70 1675.19 0.00 1675.19 1811.27 0.00 1811.27 1930.62 0.00 1930.62 2460.69 0.00 2460.69 3136.30 0.00 3136.30 3997.40 0.00 3997.40 = 411 Project: Gallatin County Roadway Improvements Project #: BOZ_13005.03 Date: 12/13/2019 Design Storm Frequency =10 years Discharge Rate, d =0.00 cfs Input values for runoff coefficients from appropriate tables. Area Area Runoff Coefficient Frequency Factor Calculation Value A A/(43560 ft2/acre)C Cf C x Cf C' C' x A (ft2)(Acres)=(C x Cf) < or = 1 (Acres) 41415 0.951 0.9 1 0.90 0.90 0.855681818 0.000 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 0 1 0.00 0.00 0 41415 0.9508 0.8557 Weighted Runoff Coefficient, Cwd SCjAj SAj Cwd x Cf x SAj =0.86 Where Cj is the adjusted runoff coefficient for surface type j and Aj is the area of surface type j Rainfall Rainfall Peak Flow Duration, t Intensity, i = Cwd x SAj x i (min) (in/hr)(ft3/s) 1 9.16 7.84 5 3.22 2.75 10 2.05 1.76 15 1.58 1.35 20 1.31 1.12 25 1.13 0.97 30 1.00 0.86 35 0.91 0.78 40 0.83 0.71 45 0.77 0.66 50 0.72 0.62 55 0.68 0.58 60 0.64 0.55 75 0.55 0.47 90 0.49 0.42 105 0.44 0.38 120 0.41 0.35 150 0.35 0.30 180 0.31 0.27 360 0.20 0.17 720 0.13 0.11 1440 0.08 0.07 2,512.78 ft3 2.75 (ft3/s) Impervious RATIONAL METHOD FOR RUNOFF CALCULATIONS Post-Project Increase in Impervious Cover Surface Type Totals = 0.9000 Cwd x Cf =0.90 Runoff Volume Discharge Volume Site Detention = = Cwd x SAj x i x t = d x t = Runoff Volume - Discharge Volume (ft3) (ft 3) (ft 3) 470.37 0.00 470.37 826.19 0.00 826.19 1053.03 0.00 1053.03 1213.60 0.00 1213.60 1342.15 0.00 1342.15 1451.18 0.00 1451.18 1546.80 0.00 1546.80 1632.55 0.00 1632.55 1710.66 0.00 1710.66 1782.65 0.00 1782.65 1849.62 0.00 1849.62 1912.36 0.00 1912.36 1971.49 0.00 1971.49 2131.64 0.00 2131.64 2272.10 0.00 2272.10 2398.05 0.00 2398.05 2512.78 0.00 2512.78 2716.90 0.00 2716.90 2895.92 0.00 2895.92 3691.03 0.00 3691.03 4704.44 0.00 4704.44 5996.10 0.00 5996.10 = 412 V:13005_03_2019-12-13_Storm_Drainage_Plan 8 (12/13/19) MTR Appendix C HYDRAULICS CALCULATIONS 413 Project Description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.033 Channel Slope 0.00500 ft/ft Normal Depth 0.40 ft Left Side Slope 25.00 ft/ft (H:V) Right Side Slope 40.00 ft/ft (H:V) Results Discharge 5.66 ft³/s Flow Area 5.20 ft² Wetted Perimeter 26.01 ft Hydraulic Radius 0.20 ft Top Width 26.00 ft Critical Depth 0.29 ft Critical Slope 0.03040 ft/ft Velocity 1.09 ft/s Velocity Head 0.02 ft Specific Energy 0.42 ft Froude Number 0.43 Flow Type Subcritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.40 ft Critical Depth 0.29 ft Channel Slope 0.00500 ft/ft Critical Slope 0.03040 ft/ft Worksheet for Conveyance Ditch 1 7/9/2018 10:12:15 AM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 1of1Page Swale 1 414 Project Description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.032 Channel Slope 0.01300 ft/ft Normal Depth 0.80 ft Left Side Slope 5.00 ft/ft (H:V) Right Side Slope 4.00 ft/ft (H:V) Results Discharge 8.14 ft³/s Flow Area 2.88 ft² Wetted Perimeter 7.38 ft Hydraulic Radius 0.39 ft Top Width 7.20 ft Critical Depth 0.73 ft Critical Slope 0.02159 ft/ft Velocity 2.83 ft/s Velocity Head 0.12 ft Specific Energy 0.92 ft Froude Number 0.79 Flow Type Subcritical GVF Input Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity Infinity ft/s Upstream Velocity Infinity ft/s Normal Depth 0.80 ft Critical Depth 0.73 ft Channel Slope 0.01300 ft/ft Critical Slope 0.02159 ft/ft Worksheet for Conveyance Ditch 2 7/9/2018 10:12:43 AM Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03] 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 1of1Page Swale 2 415 V:13005_03_2019-12-13_Storm_Drainage_Plan 9 (12/13/19) MTR Appendix D MAINTENANCE PLAN 416 December 13, 2019 Project No. BOZ 13005.03 STORM DRAINAGE FACILITY MAINTENANCE PLAN FOR GALLATIN COUNTY FAIRGROUNDS ROADWAY IMPROVEMENTS BOZEMAN, MONTANA OVERVIEW NARRATIVE The purpose of this maintenance plan is to outline the necessary details related to ownership, responsibility and cleaning schedule for the storm drainage facilities for the Gallatin County Fairgrounds. This plan has been completed in accordance with The City of Bozeman Design Standards and Specifications Policy, dated March 2004. The site stormwater improvements have been designed with the intent to meet the current City of Bozeman drainage regulations for the entire site to the extent feasible. Specific site information and criteria are described below: I. Ownership of Facilities Gallatin County Fairgrounds Gallatin County Fairgrounds will own all stormwater facilities which includes the dry wells, conveyance ditches and the detention basin. II. Inspection Thresholds for Cleaning Basin If the average depth of sediment exceeds 6 inches, clean basin Conveyance Ditches If the average depth of sediment exceeds 2 inches, clean entire ditch Dry Wells If sediment in sump exceeds 5 inches or grate is more than 25% clogged with debris, clean grate and/or structure 417 418 V:13005_03_2019-12-17_Storm_Drainage_Plan 8 (12/17/19) MTR Appendix E GEOTECHNICAL REPORT 419 Great Falls • Bozeman • Kalispell, Montana Spokane, Washington • Lewiston, Idaho REPORT OF GEOTECHNICAL INVESTIGATION ICE HOCKEY (HAYNES) PAVILION EXPANSION GALLATIN COUNTY FAIRGROUNDS, BOZEMAN, MONTANA October 2012 CLIENT: Bozeman Amateur Hockey Association PO Box 6414 Bozeman, MT 59771 Contacts: Julie Keck (406) 586-5557 Rob Pertzborn (406) 582-8988 ENGINEER: TD&H Engineering 234 E. Babcock Street, Suite 3 Bozeman, MT 59715 Contact: Kyle Scarr, P.E. (406) 586-0277 Job No. B12-060 NEW EXPANSION HAYNES PAVILION 10/5/12 420 ICE HOCKEY PAVILION EXPANSION Table of Contents GALLATIN COUNTY FAIRGROUNDS i TABLE OF CONTENTS 1.0 INTRODUCTION ............................................................................................................... 1 1.1 PURPOSE AND SCOPE ................................................................................................. 1 1.2 PROJECT DESCRIPTION .............................................................................................. 1 2.0 SITE CONDITIONS ............................................................................................................ 3 2.1 GEOLOGY AND PHYSIOGRAPHY ............................................................................. 3 2.2 SURFACE CONDITIONS .............................................................................................. 3 2.3 SUBSURFACE CONDITIONS ....................................................................................... 3 3.0 ENGINEERING ANALYSIS .............................................................................................. 6 3.1 INTRODUCTION ............................................................................................................ 6 3.2 SITE GRADING AND EXCAVATIONS ....................................................................... 6 3.3 SHALLOW SPREAD FOOTING FOUNDATION ........................................................ 6 3.4 FLOOR SLABS AND EXTERIOR FLATWORK .......................................................... 7 4.0 RECOMMENDATIONS ..................................................................................................... 8 4.1 SITE GRADING AND EXCAVATIONS ....................................................................... 8 4.2 SHALLOW SPREAD FOOTING FOUNDATION ........................................................ 9 4.3 FLOOR SLABS AND EXTERIOR FLATWORK ........................................................ 10 4.4 CONTINUING SERVICES ........................................................................................... 11 5.0 SUMMARY OF FIELD AND LABORATORY STUDIES ............................................. 12 5.1 FIELD EXPLORATIONS ............................................................................................. 12 5.2 LABORATORY TESTING ........................................................................................... 12 6.0 LIMITATIONS .................................................................................................................. 14 421 ICE HOCKEY PAVILION EXPANSION Table of Contents GALLATIN COUNTY FAIRGROUNDS ii APPENDIX Site Plan (Figure 1) Logs of Exploratory Test Pits (Figures 2 through 4) Laboratory Test Data (Figures 5 and 6) Soil Classification and Sampling Terminology for Engineering Purposes Classification of Soils for Engineering Purposes 422 ICE HOCKEY PAVILION EXPANSION Introduction GALLATIN COUNTY FAIRGROUNDS 1 GEOTECHNICAL REPORT ICE HOCKEY (HAYNES) PAVILION EXPANSION GALLATIN COUNTY FAIRGROUNDS 1.0 INTRODUCTION 1.1 PURPOSE AND SCOPE This report presents the results of our geotechnical study for the Ice Hockey Pavilion Expansion (Haynes Pavilion) located at the Gallatin County Fairgrounds in Bozeman, Montana. The purpose of the geotechnical study is to determine the general surface and subsurface conditions at the proposed site and to develop geotechnical engineering recommendations for support of the proposed structure and design of related facilities. This report describes the field work and laboratory analyses conducted for this project, the surface and subsurface conditions encountered, and presents our recommendations for the proposed foundations and related site development. Our field work included excavating three soil test pits beneath the proposed addition. Samples were obtained from the test pits and returned to our materials testing laboratory for testing. Laboratory testing was performed on select soil samples to determine engineering properties of the subsurface materials. The information obtained during our field investigations and laboratory analyses was used to develop recommendations for the design of the proposed foundation systems. The test pits excavated during our site investigation were intended to validate the subsurface soils information and testing performed in July of 1999, also by TD&H Engineering, for the original Haynes Pavilion building geotechnical report titled “Ice Hockey Pavilion, Gallatin County Fairground, Bozeman, Montana.” This study is in general accordance with the proposal submitted by Mr. Kyle Scarr, P.E., of our firm dated June 26, 2012. Our work was authorized to proceed by Ms. Julie Keck, of the Bozeman Amateur Hockey Association (BAHA) by her signed acceptance of our proposal. 1.2 PROJECT DESCRIPTION It is our understanding that the proposed project consists of, in part, a single-story, steel-framed, metal structure approximately 36,400 square feet in area and being approximately 223 by 163 423 ICE HOCKEY PAVILION EXPANSION Introduction GALLATIN COUNTY FAIRGROUNDS 2 feet. The expansion will be located west of the existing Haynes Pavilion. The new addition is proposed to be supported on conventional shallow spread footings incorporating slab-on-grade construction. The interior slab will include a refrigeration system to maintain ice conditions. It is also our understanding an under-slab heating system is being considered to prevent potential frost related problems associated with year-round use of the facility as an ice rink. Structural loads had not been provided for our use at the time of this report. For the purpose of our study, we have assumed that wall loads will be less than 4 kips per lineal foot (kpf) and column loads will be less than 100 kips. This is consistent with the design structural loads for the original Haynes Pavilion. If loadings, locations or conditions are significantly different from those described above, we should be notified to reevaluate the recommendations contained in this report. Site development will most likely include landscaping and exterior concrete flatwork. The 424 ICE HOCKEY PAVILION EXPANSION Site Conditions GALLATIN COUNTY FAIRGROUNDS 3 2.0 SITE CONDITIONS 2.1 GEOLOGY AND PHYSIOGRAPHY The site is geologically characterized as consisting of thin, surficial deposits of late Pleistocene- aged loess (eolian origin) which varies in thickness and is comprised of silt, sand and clay. In general, the fine-grained soils overlie alluvial fan and valley floor deposits of the Pleistocene age. The coarse alluvial-fan and valley deposits consist of poorly-graded, subrounded to rounded gravel with sand and cobbles with minor amounts of silt. Fan deposits are generally thin in a downslope direction with local thicknesses up to 165 feet reported. The alluvial fan deposits overlie Tertiary-aged strata. The appropriate 2009 International Building Code (IBC) seismic design parameters for the site include site coefficients of 1.102 and 1.571 for Fa and Fv, respectively. The Site Class for this site is C and the mapped spectral response accelerations at short periods (SMs) and at 1-second period (SM1) are 0.821 and 0.360, respectively. The likelihood of seismically-induced soil liquefaction or settlement for this project is low and does not warrant additional evaluation. 2.2 SURFACE CONDITIONS The proposed project site is located at the Gallatin County Fairgrounds in Bozeman, Montana, and presently consists of a gravel parking lot and landscaped areas. Based on background information, site observations, and topographic survey, the site slopes downward toward the north at slopes ranging from 1.0 to 1.5 percent. The topography is best described as nearly level. The proposed building foot print area is currently used as gravel parking areas, asphalt pathways, and lawn areas. 2.3 SUBSURFACE CONDITIONS 2.3.1 Soils. The subsurface soil conditions appear to be relatively consistent based on our exploratory excavating and soil sampling. In general, the subsurface soil conditions encountered 425 ICE HOCKEY PAVILION EXPANSION Site Conditions GALLATIN COUNTY FAIRGROUNDS 4 within the test pits consist of approximately 0.5 to 1.0 feet of fill (topsoil and gravel surfacing) over 1.8 to 2.4 feet of lean clay with sand. The lean clay with sand overlies poorly-graded gravel with sand and clay which extends to a depth of at least 10.0 feet, which was the maximum depth investigated. In general, the subsurface soils encountered are relatively consistent with those observed during the 1999 investigation by TD&H Engineering. The subsurface soils are described in detail on the enclosed test pit logs and are summarized below. The stratification lines shown on the logs represent approximate boundaries between soil types and the actual in situ transition may be gradual vertically or discontinuous laterally. FILL SOILS Fill across the site includes 1.5-inch minus gravel surfacing (TP-1 and TP-3) and lean clay with sand to gravelly lean clay (TP-2). The gravel surfacing appeared medium dense based on observation of the test pit wall and the relative difficulty to excavate. The natural moisture content of the material sampled from TP-3 was 2%. LEAN CLAY WITH SAND The lean clay with sand appeared soft to firm based on observation of the test pit wall and the relative ease to excavate. A sample of the material obtained from TP-2 contained trace gravel, 27 percent sand, and 72 percent silt and clay. The lean clay with sand exhibited a liquid limit of 33 percent and a plasticity index of 14 percent. The natural moisture content varied from 18 to 22 percent and average 20 percent. The lean clay with sand is likely compressible based on testing performed on similar soils. The upper 1 to 2 inches of this material appeared to be remnants of topsoil that was not completely removed prior to fill placement. POORLY-GRADED GRAVEL WITH SAND AND CLAY The poorly-graded gravel with sand and clay appeared very dense based on observation of the test pit wall and the relative difficulty to excavate. In situ moist densities range from 124.8 to 132.2 pounds per cubic foot (pcf) and dry densities range from 117.7 to 127.7 pcf based on in place field density testing using a nuclear densometer. The natural moisture content varied from 3 to 6 percent and averaged 5 percent. Sub-rounded to sub- angular rock particles on the order of 12-inches in diameter were abundant throughout the material. A decrease in clay content with depth was observed in all test pits. 426 ICE HOCKEY PAVILION EXPANSION Site Conditions GALLATIN COUNTY FAIRGROUNDS 5 2.3.2 Ground Water Ground water was not encountered within the test pits to the maximum depth investigated (10.0 feet). The absence of observed ground water may be directly related to the time of the subsurface investigation. Numerous factors contribute to seasonal ground water occurrences and fluctuations, and the evaluation of such factors is beyond the scope of this report. 427 ICE HOCKEY PAVILION EXPANSION Engineering Analysis GALLATIN COUNTY FAIRGROUNDS 6 3.0 ENGINEERING ANALYSIS 3.1 INTRODUCTION The primary geotechnical concern regarding this project is the presence of weak compressible lean clay soils, uncontrolled fill, and lenses of topsoil beneath the proposed slab-on-grade construction. Each of these can create a potential for settlement if not considered in design or removed. These materials should not pose significant risk to conventional shallow spread footings if the below recommendations are followed. 3.2 SITE GRADING AND EXCAVATIONS The ground surface at the project site is nearly level and slopes between 1.0 and 1.5 percent down to the north. Based on our field work and depending on the final finished floor elevation, lean clay with sand and poorly-graded gravel with sand and clay will be encountered in foundation excavations to the depths anticipated. Based on the test pits, ground water should be below the anticipated depths of footing and utility excavations. 3.3 SHALLOW SPREAD FOOTING FOUNDATION Considering the subsurface conditions encountered and the nature of the proposed construction, the structure can be supported on shallow spread footing foundations bearing on native poorly- graded gravel with sand and clay or on properly compacted structural fill extending down to native poorly-graded gravel with sand and clay. Based on our experience and using an allowable bearing pressure of 4,000 pounds per square foot (psf), we estimate the total settlement for footings will be less than ¾-inch. Differential settlement across the structure should be on the order of one-half this magnitude. The lateral resistance of spread footings is controlled by a combination of sliding resistance between the footing and the foundation material at the base of the footing and the passive earth pressure against the side of the footing in the direction of movement. Design parameters are given in the recommendations section of this report. 428 ICE HOCKEY PAVILION EXPANSION Engineering Analysis GALLATIN COUNTY FAIRGROUNDS 7 New spread footings placed adjacent to the existing structure should bear at approximately the same elevation as the existing footings and should be separated from the existing footings by a lateral distance greater than at least one footing width of the new or existing footing (whichever is widest) to avoid adverse stresses on the subgrade, footings, and stem walls. 3.4 FLOOR SLABS AND EXTERIOR FLATWORK The natural on-site soils, exclusive of all fill and topsoil, are suitable to support lightly to moderately loaded, slab-on-grade construction. A leveling course of granular fill directly below the slab is recommended to provide a structural cushion, a capillary-break from the subgrade, and a drainage medium. 429 ICE HOCKEY PAVILION EXPANSION Recommendations GALLATIN COUNTY FAIRGROUNDS 8 4.0 RECOMMENDATIONS 4.1 SITE GRADING AND EXCAVATIONS 1. All topsoil and organic material, asphalt, concrete and related construction debris, and should be removed from the proposed building areas and any areas to receive site grading fill. All existing and abandoned utilities should be relocated or removed from within the building footprint. Stripping depths should extend through all fill and topsoil lenses which were observed up to two feet below existing ground. Required stripping depths will vary across the site. 2. All fill and backfill should be non-expansive, free of organics and debris and should be approved by the project geotechnical engineer. All fill should be placed in uniform lifts not exceeding 8 inches in thickness for fine-grained soils and not exceeding 12 inches for granular soils. All fill and backfill shall be compacted to the following percentages of the maximum dry density determined by a modified proctor test which is outlined by ASTM D1557 or equivalent (e.g. ASTM D4253- D4254). a) Below Foundations or Spread Footings ............................................. 95% b) Below Slab-on-Grade Construction................................................... 92% c) Below Streets, Parking Lots, or Other Paved Areas .......................... 92% d) General Landscaping or Nonstructural Areas ................................... 90% e) Utility Trench Backfill, To Within 2 Feet of Surface ........................ 92% 3. Imported structural fill, if needed, should be non-expansive, free of organics and debris, and selected per the following gradation requirements: Screen or Sieve Size Percent Passing by Weight 3-inch 100 1½-inch 80 – 100 ¾-inch 60 – 100 No. 4 25 – 60 No. 200 10 maximum 430 ICE HOCKEY PAVILION EXPANSION Recommendations GALLATIN COUNTY FAIRGROUNDS 9 4. Develop and maintain site grades which will rapidly drain surface and roof runoff away from foundation and subgrade soils; both during and after construction. 5. Downspouts from roof drains should discharge at least 10 feet from the buildings or convey directly to a storm drain system. 6. Site utilities should be installed with proper bedding in accordance with pipe manufacturer’s requirements. 7. It is the responsibility of the Contractor to provide safe working conditions in connection with underground excavations. Temporary construction excavations greater than four feet in depth, which workers will enter, will be governed by OSHA guidelines given in 29 CFR, Part 1926. For planning purposes, subsoils encountered in the test pits classify as Type B for the lean clay with sand and Type C for the poorly-graded gravel with sand and clay. 4.2 SHALLOW SPREAD FOOTING FOUNDATION The design and construction criteria below should be observed for a spread footing foundation system. The construction details should be considered when preparing the project documents. 8. Both interior and exterior footings should bear on properly compacted native poorly-graded gravel with sand and clay or on properly compacted structural fill (meeting the requirements of Items 2 and 3) extending down to gravel. Footings should be designed for a maximum allowable soil bearing pressure of 4,000 psf provided settlements as outlined in the engineering analysis are acceptable. The limits of over-excavation and replacement with compacted structural fill should extend downward and outward laterally from the bottom edges of the footings at a 1:1 (horizontal to vertical) projection. 9. Soils disturbed below the planned depths of footing excavations should either be recompacted or be replaced with suitable compacted backfill approved by the geotechnical engineer. 10. Footings should have a minimum width of 16 inches for wall footings and 24 inches for column footings. 431 ICE HOCKEY PAVILION EXPANSION Recommendations GALLATIN COUNTY FAIRGROUNDS 10 11. Exterior footings and footings beneath unheated areas should be placed at least 48 inches below finished exterior grade for frost protection. 12. The bottom of the footing excavations should be free of cobbles and boulders to avoid stress concentrations acting on the base of the footings. 13. Lateral loads are resisted by sliding friction between the footing base and the supporting soil and by lateral pressure against the footings opposing movement. For design purposes, a friction coefficient of 0.50 and a lateral resistance pressure of 400 psf per foot of depth are appropriate for the poorly-graded gravel with sand and clay. 14. New footings placed adjacent to the existing structure should bear at the same approximate elevation and should be separated from the existing footings by a distance greater than one footing width (new or existing footing, whichever is widest). 15. A representative of the project geotechnical engineer should observe all footing excavations and backfill phases prior to the placement of concrete formwork to ensure they are in compliance with our recommendations. 4.3 FLOOR SLABS AND EXTERIOR FLATWORK 16. For normally loaded, slab-on-grade construction, a minimum 6-inch cushion course consisting of free-draining, crushed gravel should be placed beneath the slabs and compacted to a minimum of 92 percent density per ASTM D1557 (or equivalent per ASTM D4253-D4254). This material should consist of minus 3/4- inch aggregate with no more than 10 percent passing the No. 200 sieve. Prior to placing the cushion course, the upper six inches of subgrade should be compacted to 92 percent of maximum density per ASTM D1557. 17. The results of our field exploration indicate that existing fill and buried topsoil lenses will be encountered in the building area. The existing fill and topsoil should be removed below all slab areas. If over excavation is required to remove all existing fill and topsoil below the slab, structural fill meeting the requirements of Item 2 and 3 above should be used as backfill. 432 ICE HOCKEY PAVILION EXPANSION Recommendations GALLATIN COUNTY FAIRGROUNDS 11 18. The lean clay with sand is considered to have high frost susceptibility (frost group F3) according to National Cooperative Highway Research Program (NCHRP). A thermal analysis should be performed to model the maximum depth of sustained frost penetration. The results of the thermal analysis should be used to provide subgrade improvement recommendations. Without a thermal analysis, the only positive way to prevent potential frost heave is to excavate the fine-grained soils below the ice rink down to the gravel and backfill with compacted nonfrost- susceptible granular fill or as previously mentioned, placement an under-slab heating system below the refrigerated slab to prevent freezing of the subsurface soil. 19. Geotechnically, an underslab vapor barrier is not required. 4.4 CONTINUING SERVICES Three additional elements of geotechnical engineering service are important to the successful completion of this project. 20. Consultation between the geotechnical engineer and the design professionals during the design phases is highly recommended. This is important to ensure that the intentions of our recommendations are incorporated into the design, and that any changes in the design concept consider the geotechnical limitations dictated by the on-site subsurface soil and ground water conditions. 21. Observation, monitoring, and testing during construction is required to document the successful completion of all earthwork and foundation phases. A geotechnical engineer from our firm should observe the excavation, earthwork, and foundation phases of the work to determine that subsurface conditions are compatible with those used in the analysis and design. 22. During site grading, placement of all fill and backfill should be observed and tested to confirm that the specified density has been achieved. We recommend that the owner maintain control of the construction quality control by retaining the services of a construction materials testing laboratory. We are available to provide construction inspection services as well as materials testing of compacted soils and the placement of Portland cement concrete. 433 ICE HOCKEY PAVILION EXPANSION Summary of Field and Laboratory Studies GALLATIN COUNTY FAIRGROUNDS 12 5.0 SUMMARY OF FIELD AND LABORATORY STUDIES 5.1 FIELD EXPLORATIONS The field exploration program was conducted on August 23, 2012. A total of three test pits were excavated to depths ranging from 9.3 to 10.0 feet at the locations shown on Figure 1 to observe subsurface soil and ground water conditions. The tests pits were excavated using a Takeuchi TB 250 excavator. The subsurface exploration and sampling methods used are indicated on the attached test pit logs. The test pits were logged by Mr. Kyle Scarr, P.E. of TD&H Engineering. The approximate locations and surface elevations of the exploratory test pits are shown on Figure 1. Logs of all soil test pits, which include soil descriptions and sample depths are presented on the Figures 2 though 4. No evidence of ground water was encountered. 5.2 LABORATORY TESTING Samples obtained during the field exploration were returned to our materials laboratory where they were observed and visually classified in general accordance with ASTM D2487, which is based on the Unified Soil Classification System. Representative samples were selected for testing to determine the engineering and physical properties of the soils in general accordance with ASTM or other approved procedures. Tests Conducted: To determine: Natural Moisture Content Representative moisture content of soil at the time of sampling. Grain-Size Distribution Particle size distribution of soil constituents describing the percentages of clay/silt, sand and gravel. Atterberg Limits A method of describing the effect of varying water content on the consistency and behavior of fine-grained soils. UU Shear Strength (Field) The undrained, unconfined shear strength (su) of cohesive soils as determined in the field by a pocket penetrometer. 434 ICE HOCKEY PAVILION EXPANSION Summary of Field and Laboratory Studies GALLATIN COUNTY FAIRGROUNDS 13 The laboratory testing program for this project consisted of five moisture-visual analyses, one sieve (grain-size distribution) analysis, and one Atterberg Limits analysis. The grain-size distribution curves and Atterberg limits are presented on Figures 5 and 6. In addition, in place field density tests using a nuclear densometer were conducted. The results of field density testing, field shear strength testing, and water content analyses are presented on the test pit logs. 435 ICE HOCKEY PAVILION EXPANSION Limitations GALLATIN COUNTY FAIRGROUNDS 14 6.0 LIMITATIONS This report has been prepared in accordance with generally accepted geotechnical engineering practices in this area for use by the client for design purposes. The findings, analyses, and recommendations contained in this report are based on site conditions encountered and further assume that the results of the exploratory test pits are representative of the subsurface conditions throughout the site, that is, that the subsurface conditions everywhere are not significantly different from those disclosed by the subsurface study. If during construction, subsurface conditions appear different from those encountered during our study, this office should be advised at once so we can review these conditions and reconsider our recommendations, when necessary. Unanticipated soil conditions are commonly encountered and cannot be fully determined by a limited number of soil test pits and laboratory analyses. Such unexpected conditions frequently require that additional expenditures be made to obtain a properly constructed project. Therefore, some contingency fund is recommended to accommodate such potential extra costs. If substantial time has elapsed between the submission of this report and the start of work at the site, or if conditions have changed because of natural causes or construction operations at or adjacent to the site, we recommend that this report be reviewed to determine the applicability of the conclusions and recommendations considering the time lapse or changed conditions. If you desire, we will review those portions of the plans and specifications which pertain to earthwork and foundations to determine if they are consistent with our recommendations. In addition, we are available to observe construction, particularly the placement and compaction of all fill, preparation of all foundations and quality control testing of Portland cement concrete. This report was prepared for the exclusive use of the owner and architect and/or engineer in the design of the subject facility. It should be made available to prospective contractors and/or the contractor for information on factual data only and not as a warranty of subsurface conditions such as those interpreted from the test pit logs and presented in discussions of subsurface conditions included in this report. Prepared by: Reviewed by: Kyle L. Scarr, P.E. Craig R. Nadeau, P.E. Geotechnical Engineer Geotechnical Engineer 436 QUALITY CHECK: DESIGNED BY: DRAWN BY: CAD NO. JOB NO. DATE: B12-060 FIG 1 MONTANAWASHINGTON IDAHO GREAT FALLS-BOZEMAN-KALISPELL LEWISTONSPOKANE Engineering tdhengineering.com HAYNES PAVILION EXPANSION BOZEMAN, MONTANA APPROXIMATE TEST PIT LOCATIONS KLS NA NA 10/3/12 B12-060 FIGURE 1437 Log of Test Pit TP-1 Figure No. Sheet of 2 1 1GRAPHICLOG01020304050 0 0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION LEGEND DEPTH(FEET)Haynes Pavilion Expansion Bozeman, Montana THOMAS, DEAN & HOSKINS, INC. ENGINEERING CONSULTANTS AUGUST 23, 2012 B12-060(FEET)1 8 12 9.3Groundwater Not EncounteredDuring ExcavationWell-graded GRAVEL with sand and silt, relatively medium dense, dry, brown to gray, 1.5" minus gravel surface course APPROXIMATE SURFACE ELEVATION: SURFACE: Logged By: Kyle L. Scarr, P.E.Excavated By:Earth Surgeons Takeuchi TB 250 Gravel surfaced parking lot 4797.5 Feet 2 3 4 5 6 7 9 10 11 13 14 15 16 Lean CLAY with sand, relatively soft to firm, dry, brown to tan, upper 2" appears to have been topsoil Poorly-graded GRAVEL with sand and clay, relatively very dense, slightly moist, brown variegated, less fines with depth, cobbles and boulders up to 1' in diameter Bottom of Test Pit 3.0 0.6 Average qu = 2.5 tsf 5.0' - 6.0' Wet density: 129.2 pcf Dry density: 125.6 pcf Moisture: 2.9% 438 Log of Test Pit TP-2 Figure No. Sheet of 3 1 1GRAPHICLOG01020304050 0 0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION LEGEND DEPTH(FEET)Haynes Pavilion Expansion Bozeman, Montana THOMAS, DEAN & HOSKINS, INC. ENGINEERING CONSULTANTS AUGUST 23, 2012 B12-060(FEET)1 8 12 10.0Groundwater Not EncounteredDuring ExcavationFILL: Lean clay with sand, relatively soft, dry, brown APPROXIMATE SURFACE ELEVATION: SURFACE: Logged By: Kyle L. Scarr, P.E.Excavated By:Earth Surgeons Takeuchi TB 250 Lightly grassed lawn area 4799.0 Feet 2 3 4 5 6 7 9 10 11 13 14 15 16 FILL: Gravelly lean clay, relatively firm, dry, brown, gravel up to 3" in diameter Poorly-graded GRAVEL with sand and clay, relatively very dense, slightly moist, brown variegated, less fines with depth, cobbles and boulders up to 1' in diameter Bottom of Test Pit 3.4 0.5 4.0'- 5.0' Wet density: 132.2 pcf Dry density: 127.7 pcf Moisture: 3.5% 1.0 Lean CLAY with sand, relatively soft to firm, slightly moist, brown to tan, upper 1" appears to have been topsoil 439 Log of Test Pit TP-3 Figure No. Sheet of 4 1 1GRAPHICLOG01020304050 0 0 10 30 40 5020SAMPLEDEPTHWATERGROUNDSOIL DESCRIPTION LEGEND DEPTH(FEET)Haynes Pavilion Expansion Bozeman, Montana THOMAS, DEAN & HOSKINS, INC. ENGINEERING CONSULTANTS AUGUST 23, 2012 B12-060(FEET)1 8 12 10.0Groundwater Not EncounteredDuring ExcavationWell-graded GRAVEL with sand and silt, relatively medium dense, dry, brown to gray, 1.5" minus gravel surface course APPROXIMATE SURFACE ELEVATION: SURFACE: Logged By: Kyle L. Scarr, P.E.Excavated By:Earth Surgeons Takeuchi TB 250 Gravel surfaced parking lot 4799.5 Feet 2 3 4 5 6 7 9 10 11 13 14 15 16 Lean CLAY, relatively firm, slightly moist, dark brown to black, trace sand, appears to have been topsoil Poorly-graded GRAVEL with sand and clay, relatively very dense, slightly moist, brown variegated, less fines with depth, cobbles and boulders up to 1' in diameter Bottom of Test Pit 2.3 0.5 5.0' - 6.0' Wet density: 124.8 pcf Dry density: 117.7 pcf Moisture: 6.0% 440 Tested By: SSS Checked By: 9-4-2012 (no specification provided) PL= LL= PI= D90= D85= D60= D50= D30= D15= D10= Cu= Cc= USCS= AASHTO= * Lean CLAY w/sand 3/8" #4 #10 #20 #40 #60 #80 #100 #200 100.0 99.3 98.3 96.8 93.9 90.0 86.8 84.8 72.0 19 33 14 0.2507 0.1529 CL A-6(8) Report No: A-6178-206 Intrinsik Architecture Haynes Pavilion Geotech B12-060 Material Description Atterberg Limits Coefficients Classification Remarks Location: TP Sample Number: A-6178 Depth: 2'-2.5'Date: Client: Project: Project No: Figure SIEVE PERCENT SPEC. *PASS? SIZE FINER PERCENT (X=NO)PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.00010.0010.010.1110100 % +3"Coarse % Gravel Fine Coarse Medium % Sand Fine Silt % Fines Clay 0.0 0.0 0.7 1.0 4.4 21.9 72.06 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200Particle Size Distribution Report 5 Bozeman Amateur Hockey Association 441 Tested By: TJR Checked By: Lean CLAY w/sand 33 19 14 93.9 72.0 CL B12-060 Intrinsik Architecture MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS Project No. Client:Remarks: Project: Figure Location: TP Depth: 2'-2.5'Sample Number: A-6178PLASTICITY INDEX0 10 20 30 40 50 60 LIQUID LIMIT 0 10 20 30 40 50 60 70 80 90 100 110 CL-ML C L or O L C H or O H ML or OL MH or OH Dashed line indicates the approximate upper limit boundary for natural soils 47 LIQUID AND PLASTIC LIMITS TEST REPORT Report No: A-6178-207Haynes Pavilion Geotech Bozeman Amateur Hockey Association 6 442 Great Falls, Kalispell, Bozeman, Montana Spokane, Washington, Lewiston, Idaho THOMAS, DEAN & HOSKINSEngineering Consultants SOIL CLASSIFICATION AND SAMPLING TERMINOLOGY FOR ENGINEERING PURPOSES 12" 3" 3/4" No.4 No.10 No.40 No.200 <No.200 SILTS & CLAYSBOULDERSCOBBLESGRAVELSSANDS PARTICLE SIZE RANGE (Distinguished By Atterberg Limits)FineCoarse FineMediumCoarse Sieve Openings (Inches)Standard Sieve Sizes CL - Lean CLAY ML - SILT OL - Organic SILT/CLAY CH - Fat CLAY MH - Elastic SILT OH - Organic SILT/CLAY SW - Well-graded SAND SP - Poorly-graded SAND SM - Silty SAND SC - Clayey SAND GW - Well-graded GRAVEL GP - Poorly-graded GRAVEL GM - Silty GRAVEL GC - Clayey GRAVEL * Based on Sampler-Hammer Ratio of 8.929 E-06 ft/lbf and 4.185 E-05 ft^2/lbf for granular and cohesive soils, respectively (Terzaghi) STANDARD PENETRATION TEST (ASTM D1586) RELATIVE DENSITY*RELATIVE CONSISTENCY* Granular, Noncohesive (Gravels, Sands, & Silts)Fine-Grained, Cohesive (Clays) Very Loose Loose Medium Dense Dense Very Dense Very Soft Soft Firm Stiff Very Stiff Hard 0-2 3-4 5-8 9-15 15-30 +30 0-4 5-10 11-30 31-50 +50 Standard Penetration Test (blows/foot) Standard Penetration Test (blows/foot) PLASTICITY CHART 0 10 16 20 30 40 50 60 70 80 90 100 110 60 50 40 30 20 107 4 C L or O LC H or O H ML or OL MH or OH CL-ML "U - LIN E""A - LIN E"LIQUID LIMIT (LL)PLASTICITY INDEX (PI)For classification of fine-grained soils and thefine-grained fraction of coarse-grained soils. Equation of "A"-line Horizontal at PI = 4 to LL = 25.5, then PI = 0.73 (LL-20) Equation of "U"-line Vertical at LL = 16 to PI = 7, then PI = 0.9 (LL-8) 443 Great Falls, Kalispell, Bozeman, Montana Spokane, Washington, Lewiston, Idaho THOMAS, DEAN & HOSKINSEngineering Consultants ASTM D2487 CLASSIFICATION OF SOILS FOR ENGINEERING PURPOSES Flow Chart For Classifying Coarse-Grained Soils (More Than 50 % Retained On The No. 200 Sieve) Flow Chart For Classifying Fine-Grained Soils ( 50 % Or More Passes The No. 200 Sieve) <5% fines 5-12% fines >12% fines <5% fines 5-12% fines >12% fines Well-graded GRAVELWell-graded GRAVEL with sandPoorly-graded GRAVELPoorly-graded GRAVEL with sand Well-graded GRAVEL with silt Well-graded GRAVEL with silt and sandWell-graded GRAVEL with clay (or silty clay)Well-graded GRAVEL with clay and sand (or silty clay and sand) Poorly-graded GRAVEL with silt Poorly-graded GRAVEL with silt and sand Poorly-graded GRAVEL with clay (or silty clay)Poorly-graded GRAVEL with clay and sand (or silty clay and sand) Silty GRAVELSilty GRAVEL with sandClayey GRAVELClayey GRAVEL with sandSilty, clayey GRAVEL Silty, clayey GRAVEL with sand Well-graded SAND Well-graded SAND with gravel Poorly-graded SANDPoorly-graded SAND with gravel Well-graded SAND with silt Well-graded SAND with silt and gravel Well-graded SAND with clay (or silty clay)Well-graded SAND with clay and gravel (or silty clay and gravel) Poorly-graded SAND with siltPoorly-graded SAND with silt and gravelPoorly-graded SAND with clay (or silty clay) Poorly-graded SAND with clay and gravel (or silty clay and gravel) Silty SANDSilty SAND with gravelClayey SAND Clayey SAND with gravel Silty, clayey SAND Silty, clayey SAND with gravel <15% sand>15% sand <15% sand >15% sand <15% sand>15% sand <15% sand >15% sand <15% sand>15% sand<15% sand>15% sand <15% sand>15% sand<15% sand>15% sand<15% sand >15% sand <15% gravel >15% gravel <15% gravel>15% gravel <15% gravel>15% gravel<15% gravel>15% gravel <15% gravel >15% gravel<15% gravel>15% gravel <15% gravel >15% gravel<15% gravel>15% gravel<15% gravel>15% gravel Lean CLAYLean CLAY with sandLean CLAY with gravelSandy lean CLAY Sandy lean CLAY with gravel Gravelly lean CLAY Gravelly lean CLAY with sand Silty CLAY Silty CLAY with sand Silty CLAY with gravel Sandy silty CLAYSandy silty CLAY with gravelGravelly silty CLAYGravelly silty CLAY with sand SILT SILT with sandSILT with gravelSandy SILTSandy SILT with gravel Gravelly SILT Gravelly SILT with sand Fat CLAYFat CLAY with sand Fat CLAY with gravel Sandy fat CLAYSandy fat CLAY with gravelGravelly fat CLAYGravelly fat CLAY with sand Elastic SILT Elastic SILT with sand Elastic SILT with gravelSandy elastic SILTSandy elastic SILT with gravelGravelly elastic SILT Gravelly elastic SILT with sand %sand > %gravel %sand < %gravel <15% gravel>15% gravel<15% sand>15% sand %sand > %gravel %sand < %gravel<15% gravel>15% gravel<15% sand >15% sand %sand > %gravel%sand < %gravel <15% gravel>15% gravel<15% sand>15% sand %sand > %gravel%sand < %gravel<15% gravel>15% gravel<15% sand >15% sand %sand > %gravel %sand < %gravel <15% gravel>15% gravel<15% sand>15% sand fines=ML or MH fines=CL or CH (or CL-ML) fines=ML or MH fines=CL or CH (or CL-ML) fines=ML or MH fines=CL or CH fines=CL-ML fines=ML or MH fines=CL or CH (or CL-ML) fines=ML or MH fines=CL or CH (or CL-ML) fines= ML or MH fines=CL or CH fines=CL-ML <30% plus No. 200 >30% plus No. 200 <30% plus No. 200 >30% plus No. 200 <30% plus No. 200 >30% plus No. 200 <30% plus No. 200 >30% plus No.200 <30% plus No. 200 >30% plus No. 200 Cu>4 and 1<Cc<3 Cu<4 and/or 1>Cc>3 Cu>4 and 1<Cc<3 Cu<4 and/or 1>Cc>3 Cu>6 and 1<Cc<3 Cu<6 and/or 1>Cc>3 Cu>6 and 1<Cc<3 Cu<6 and/or 1>Cc>3 CL CL-ML ML CH MH PI>7 and plotson or above"A" - line 4<PI<7 andplots on or above"A" - line PI<4 or plotsbelow "A" - line PI plots on orabove "A" - line PI plots below"A" - line GRAVEL%gravel > %sand SAND%sand >%gravel LL>50(inorganic) LL<50(inorganic) GW GP GW-GM GW-GC GP-GM GP-GC GM GC GC-GM SW SP SW-SM SW-SC SP-SM SP-SC SM SC SC-SM <15% plus No. 20015-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 200 15-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 200 15-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 20015-29% plus No. 200 %sand > %gravel %sand < %gravel <15% plus No. 20015-29% plus No. 200 %sand > %gravel %sand < %gravel 444