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HomeMy WebLinkAbout11 - Storm ReportPage 2 of 6 Table of Contents 1 Introduction ......................................................................................................................... 3 2 Proposed Development ....................................................................................................... 3 2.1 Project Location and Description .................................................................................. 3 2.2 Development Description ............................................................................................. 3 2.3 Development Horizon .................................................................................................. 3 3 Existing Area Conditions ..................................................................................................... 3 3.1 Existing Land Cover and Slopes .................................................................................. 3 3.2 NRCS Soils .................................................................................................................. 4 3.3 Site Groundwater Levels .............................................................................................. 4 3.4 Existing Drainage Features .......................................................................................... 4 4 Major Drainage Basins ........................................................................................................ 4 5 Methodologies .................................................................................................................... 4 5.1 Design Methodology .................................................................................................... 4 5.2 Storm Water Runoff Analyses ...................................................................................... 5 5.3 Storm Drain Piping ....................................................................................................... 5 5.4 Storm water Retention Facilities................................................................................... 5 6 Maintenance ....................................................................................................................... 6 7 Conclusions ........................................................................................................................ 6 List of Exhibits Exhibit A Vicinity Map Exhibit B NWX Phase 2 Preliminary Plat Exhibit C Post-Development Drainage Basins List of Appendices Appendix A NRCS Soil Report Appendix B Groundwater Data Appendix C Preliminary Storm Water Calculations Appendix D Operation and Maintenance Manual Page 3 of 6 1 INTRODUCTION This design report summarizes the preliminary plan for management of storm water runoff from Phase 2 of the Northwest Crossing subdivision located in Bozeman, Gallatin County, Montana. The information contained in this report summarizes the basis of design for necessary storm drainage improvements. The methodology and analysis procedures utilized in the design of the subdivision storm water management improvements are based on the standards found in the City of Bozeman Design Standards and Specifications Policy with Addendum Numbers 1 thru 6, dated May 1, 2017 (City of Bozeman Public Works Department – Engineering Division). 2 PROPOSED DEVELOPMENT 2.1 Project Location and Description The following is the legal description for the property. Tract 5 of Certificate of Survey No. 2552, located in the NE1/4 of Section 4, Township 2 South, Range 5 East, Principal Meridian, Gallatin County, Montana. The Northwest Crossing development is a proposed 160-acre mixed-use neighborhood bordered by Cottonwood Street (principal arterial) to the east, Baxter Lane (minor arterial) to the north, Laurel Parkway (collector) to the west and West Oak Street (principal arterial) to the south. This project is located within the City of Bozeman, Montana. See the vicinity map (Exhibit A) for location details. Two waterways bisect the property. Baxter Creek flows north through the western portion of the parcel. Baxter Ditch flows north through the center of the property. Phase 2 consists of 43.98 acres in the northeast corner of the proposed subdivision. 2.2 Development Description Phase 2 of Northwest Crossing is zoned REMU and consists of approximately 358 residential homes. This includes small lot single family homes, duplexes and townhomes. See proposed layout in Exhibit B: Preliminary Plat. 2.3 Development Horizon Phase 2 of the Northwest Crossing Subdivision is to begin development a soon as the entitlement approvals are in place. 3 EXISTING AREA CONDITIONS 3.1 Existing Land Cover and Slopes The existing property is primarily vacant, agricultural land. The existing slopes range from 0% to 4%, generally draining from south to north. Baxter Ditch flows through the center of the property, while Baxter Creek flows across the western portion. Public infrastructure associated with phase 1 of the Northwest Crossing subdivision was constructed in 2021. Private site development is scheduled to begin in 2022. Page 4 of 6 3.2 NRCS Soils Data on existing site soils is provided in the Gallatin County Area, Montana Soil Survey dated September 16, 2019 through Web Soil Survey (WSS) operated by the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS). According to information obtained from WSS, the Phase 1 contains two soil types – Hyalite- Beaverton Complex and Meadowcreek Loam. See Appendix A for the complete Soil Resource Report. 3.3 Site Groundwater Levels Groundwater levels beneath the proposed subdivision experience seasonal variations but are generally quite high. Morrison-Maierle observed groundwater levels in 8 wells between May 24, 2019 and November 11, 2019. Water & Environmental Technologies (WET) prepared a report and designed a system of ground water drains to help lower the ground water in the subdivision. See complete groundwater data in Appendix B. The high groundwater will require fill in most areas to ensure storm water facilities are not inundated. Storm ponds will be designed to keep the bottom of the pond above the estimated seasonal high ground water level. 3.4 Existing Drainage Features Two existing waterways flow from south to north through the property. The majority of the runoff from Phase 2 will flow towards Baxter Ditch. All proposed development will maintain a minimum 50 ft setback from the designated wetland boundary. 4 MAJOR DRAINAGE BASINS Phase 2 of the Northwest Crossing Subdivision will be divided into eight (8) drainage basins. One main basin will capture about 70% of the area down the middle of the subdivision and convey runoff to an underground detention system. Seven smaller, shallow surface retention ponds will be developed in open space areas along the roadways. Runoff will be directed from alleys and roads via curb cuts and sidewalk chases as needed. This approach will allow for some of the runoff to be treated closer to the source. Residential lots will be graded so that runoff will flow towards the public rights-of-way. Overflow from the retention ponds will flow back into the streets. Overflow from the larger detention basin will be discharged to Baxter Ditch. The north half of Baxter Lane will drain to the north side of the road, though additional right-of-way and easement(s) for temporary storm ponds will be required for the proposed infrastructure improvements to take place. This negotiation is in progress. See Exhibit C for more drainage basin details. 5 METHODOLOGIES This section documents the methodologies and assumptions used to conduct the storm water runoff analyses for the proposed development. Preliminary drainage plan methodology and analyses are based on the City of Bozeman’s Design Standards and Specifications Policy. 5.1 Design Methodology The storm water management system for the proposed development utilizes a system of curb, gutter, inlets, piping, underground detention facilities, and surface retention basins to collect, convey, and store storm water runoff. Summaries of runoff estimates and pond volumes are provided in the sections that follow. Page 5 of 6 5.2 Storm Water Runoff Analyses Storm water runoff analyses were performed using the Rational Method for post-development conditions. The analyses included evaluations of the 25-year design storm recurrence interval for inlet and piping system design. Detailed calculations are included in Appendix C. 5.3 Storm Drain Piping The storm drain piping system for the proposed development is designed to have maximum reliability of operation, minimal maintenance requirements, and to ensure that inlets function to their design capacities while meeting necessary area drainage requirements. The 25-year design storm has been selected as the basis for design as that is the City of Bozeman requirement from the Design Standards and Specifications Policy. These require that storm drain piping be designed to have a minimum velocity of 3.0 feet per second (fps) at the design depth of flow, or when flowing full, to prevent sediment deposits. In addition, pipes will be designed to be above the seasonal high groundwater level to prevent groundwater infiltration to pipes, structures and ponds. Inlets will be placed at all low points in the curb line and at intervals to limit gutter flow depth to 0.15’ below the top of the curb. Inlets and pipes will be designed to convey a 25-year storm runoff from ROWs and private lots. Inlet locations and required spacing will be developed later as the infrastructure design is finalized. 5.4 Storm water Retention Facilities Phase 2 storm water runoff will be stored in one large underground detention basin at the north end of the subdivision along Baxter Road and eight separate smaller retention surface ponds scattered throughout. Capacities will be designed to store runoff from a 10-year 2-hr See the tables below for basin areas and minimum required storage volumes. Also, see Exhibit C for basin locations. Detention Basin Basin Number Total Area (acres) Weighted C' Pre- Dev Qp (cfs) First 1/2" Vol. (cf) Min. Detention Vol. (cf) 1 31.67 0.63 5.64 35991 26205 Retention Basins Basin Number Total Area (acres) Weighted C'Q (cfs) First 1/2" Vol. (cf) Min. Retention Vol. (cf) 2 0.87 0.63 0.22 1073 1605 3 1.05 0.70 0.30 1328 2160 4 1.43 0.68 0.40 1800 2855 5 1.57 0.68 0.44 1976 3140 6 2.37 0.67 0.65 2974 4664 7 3.64 0.65 0.96 4222 6940 8 0.82 0.70 0.24 1042 1694 9 1.71 0.63 0.44 2118 3168 Page 6 of 6 6 MAINTENANCE Storm drain inlets, catch basins, and piping should be inspected at least once per year and following large storm events. Any necessary repair or maintenance should be prioritized and scheduled through the spring, summer, and fall. These items may include inspecting for any damage, removing blockages, cleaning, and flushing the length of pipes, establishing vegetation on bare slopes at or near inlets, and sediment removal. Maintenance of the retention basin is also essential. General objectives of maintenance are to prevent clogging, standing water and the growth of weeds and wetland plants. This requires frequent unclogging of the outlets, inlets, and mowing. Cleaning out sediment with earth-moving equipment may also be necessary in 10 to 20 years. Underground storm water storage facilities will need inspection and maintenance according to manufacturer’s specifications and recommendations. An Operation and Maintenance Manual is included in Appendix D. 7 CONCLUSIONS Runoff from the development of Phase 2 right-of-ways and residential lots will be conveyed to retention ponds and one large detention system for storage and treatment. Roadways, inlets, pipes and ponds will be designed to meet all City of Bozeman Design standards. A comprehensive drainage plan will be developed with the infrastructure construction plans to ensure the proposed storm water management system is adequate. Exhibit A Vicinity Map 11THSAVE19THNAVE27THNAVE15THNAVEINTERSTATE 90 191HUFFINELN W LINCOLN ST W GARFIELD ST W COLLEGE W BABCOCK ST MAIN STW COTTONWOODRD235 BAXTER LN F R O N T A G E R D OAK STW 27THAVENDURSTON RDDAVISLNPROJECT LOCATION HARPER-RDPUCKETTSPRINGHILLRDV A L L E Y R D C E N T E R E NAVEFERGUSONengineerssurveyorsplannersscientists 2880 Technology Boulevard West Bozeman, MT 59718 Phone: (406) 587-0721 Fax: (406) 922-6702 VICINITY MAP SCALE:1" = 3000' Exhibit B NWX Phase 2 Preliminary Plat ESESESDYH II MW MW MW MW MW MW MW S S S S S TP TP TP TP TP TP TP TP TP TP TP TP TP WV ESESESESESESESESESESESESESESESESESESD I II I I I I T CO CO CO CO COCO CO CO E27S E27SSTP MWMW MW MW MW MW MW MW MW TV I I I IWVEWEW GV S T S0°59'41"W 2627.49'N89°27'46"E 2675.75' 203 4716.36 SECTION CORNER T2S R5E SECTION 33-34-4-5 DAMAGED AC SS8S8S8S8S8S8S8S8S8S8S8S12S 12S 12S 12S 12S 12S 12S 12S 8S8S 8S 8S 8S8S8S8S8S8S12S12S12S12S12S12S12S12S12S12S 12S 12S 12S 12S 21S21S21S21S21S21S21S21S21S21S21S21S21S21S21S8S 8S 8S 8S 8S 8W 8W 8W 8W 8W8W8W8WWWWW8W8W8W8W8W8W8W8W8W8W8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W8W8W8W8W8W8W8W8W8W8W8W8W8W 8W BFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBFBF BF BF BF BF HH HH HHHHHHHH HHHHHHHHHHHHHHHHHH8W8W8W8W8W8S8S 8W 8W8S8S8S8S8S8S8S8S 8S8S8S8S8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8W8S8S8S8S8S8W8W8W8S8S8S8S8S8S8W8W8W8W8W8W8S8S8S8S8W8W8W8W8W8W8W8W8W8S8S8S8S 21S21S21S21S21S21S21S21S21S21S21S21S21S21S21S8S8S8S8S8S 8S 8S 8SDYHDYH DYHDYH DYH DYH DYHDYH DYH DYH DYH DYHDYH DYH DYHDYHDYH 8W 8W 8W 8W 8W 8W 8S 8S 8S 8S 8S 8S8W8W8W8W8W8W8W8W8W8W8W8W8W8S8S8S8S8W 8W 8W 8W 8W 8W 8W8W8W8W8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W 8W8W8W8W8W8W8W8W 8W8W8W8W8W8W8W8S8S8S8S8S8S8S 8S 8S 8S 8W8W8S8S8S8S8S8S8S8W8W8W8W8W8S8S8SDYHDYH8W8S8W8S8W8S8W 8S8W8S8W8S8W8W8S8W8S8W8S8W8S8W8W8W8W8S8W8W8W8S8S8W 8S 8S8S8S8S8WDYHDYH 21S 21S 21S 21S 27S 27SSSSSCO CO 8S 8S 8S 8S 8S 8S 8S 8S 8S 8S 21S 21S 21S 21S 21S 21S 21S 21S 21S 21S 21S 8S8W8W 8S8S 8S 8S 8W 8W 8S 8S 21S 21S 21S 21S 27S 27SSSSSCO CO C1 C2C3 C4C5©COPYRIGHT MORRISON-MAIERLE, INC.,2022 PLOTTED DATE: Apr/01/2022 PLOTTED BY: cody farley DRAWING NAME: N:\6787\002 - NW Crossing Ph II Pre Plat\ACAD\Survey\6787-002_NWX-PH-2_PLOT.dwg 1/4 SEC.SECTION TOWNSHIP RANGE PROJ. #:SHEET OF PRINCIPAL MERIDIAN, MONTANA COUNTY, MONTANADATE: SCALE: CLIENT: FIELD WORK: DRAWN BY: CHECKED BY: engineers surveyors planners scientists MorrisonMaierle 2880 Technology Blvd West Bozeman, MT 59718 Phone: 406.587.0721 Fax: 406.922.6702 142SEE TITLE GALLATIN 6787.002 1" = 100' 02/2022 MEE CJF MMI 5E 2S 04NE BUSH/HEDGE DECIDUOUS TREE CONIFEROUS TREE SIGN FIRE HYDRANT WATER VALVE SANITARY SEWER MH STORM DRAIN MH STORM DRAIN INLET DYHWV LIGHT POLE GUY ANCHOR POWER POLE TELEPHONE PEDESTAL/BOX WATER CURB STOP CONTROL POINTS MAILBOX WATER WELL ELECTRICAL BOX LEGEND ELECTRICAL TRANSFORMER BOX DELINEATOR EDGE OF ASPHALT FLOWLINE OF CURB//////TOP BACK OF CURB SIDEWALK EDGE OF GRAVEL WOOD FENCE CENTERLINE ROAD WATER MAIN W/ SIZE8 W SEWER MAIN W/ SIZE8 SS STORM DRAIN W/ SIZE8 SD OVERHEAD POWER LINE BURIED TELEPHONE LINE BURIED GAS LINE BURIED ELECTRIC LINE (CONTOUR INTERVAL = 0.5') EXISTING CONTOUR - MAJOR EXISTING CONTOUR - MINOR WATER MAIN W/ SIZE (GRAPHICAL)8 W WATER SERVICEWSWSWSWS WATER SERVICE (GRAPHICAL)WS WS WS WS SEWER MAIN W/ SIZE (GRAPHICAL)8 SS SEWER SERVICEssssssss SEWER SERVICE (GRAPHICAL)ss ss ss ss BURIED FIBER OPTIC CHAIN LINK FENCE WIRE FENCE AIR CONDITIONING UNIT MONITORING WELL PLI Z O NI N G BOZE M A N C O M M U NI T Y PLA N F U T U R E L A N D U S E: PRES E N T R U R A L BOZ E M A N C O M M U NI T Y PLAN F U T U R E L A N D U S E: RESI E N TI A L BOZ E M A N C O M M U NI T Y PLAN F U T U R E L A N D USE: R E SI D E N TI A L PAR C E L 1 COS 2 5 5 3 CITY O F BOZE M A N FERN & V E S T A AND E R S O N DELINEATED WETLAND BOUNDARY ZONE 1 WATERCOURSE SETBACK ZONE 2 WATERCOURSE SETBACK HARVEST PARKWAY (71')COTTONWOOD ROAD (120')BAXTER LANE 100') PRELIMINARY PLAT NORTHWEST CROSSING SUBDIVISION PH. 2 SEE SHE E T 3 SEE SHE E T 4 SEE SHE E T 5 SEE SHE E T 6 SEE SHE E T 7 SEE SHE E T 1 0 SEE SHE E T 1 3 SEE SHE E T 1 2 SEE SHE E T 9 SEE SHE E T 8 SEE SHE E T 1 1 OWNER WILLIAMS COMMUNITIES, LLC ZONING CITY OF BOZEMAN - REMU LOT 1 5 NWX P H 1 LOT 1 4 NWX P H 1 LOT 7 NWX P H 1 LOT 8 NWX P H 1 LOT 1 0 NWX P H 1 LOT 1 1 NWX P H 1 LOT 9 NWX P H 1 LOT 6 NWX P H 1 LOT 5 NWX P H 1 LOT 3 NWX P H 1 LOT 2 NWX P H 1 LOT 1 NWX P H 1 REST RI C T E D L O T 1 3 NWX P H 1 REST RI C T E D L O T 1 1 NWX P H 1 BAXTER DITCH WILDWOOD LANE (60') STREET "B" (60') TOUCHSTONE LANE (60') DAYSPRING AVE (60')DAYSPRING AVE (60')TWIN LAKES AVE (60')ROSA WAY (60')BLOCK 1 BLOCK 2 BLOCK 3 BLOCK 4 BLOCK 5 BLOCK 6 BLOCK 9 BLOCK 11 BLOCK 10 BLOCK 7 BLOCK 8 1' NO ACCESS 1' NO ACCESS RESTRICTED LOTS 1-5 OF PHASE 1 OF NORTHWEST CROSSING SUBDIVISION, SITUATED IN THE NE1/4 OF SECTION 4, TOWNSHIP 2 SOUTH, RANGE 5 EAST, PRINCIPAL MERIDIAN, CITY OF BOZEMAN, GALLATIN COUNTY, MONTANA. BASIS OF BEARING Bobcat Coordinate System, NAD83(2011) per the "Rocky Mountain Tribal Coordinate Reference System" Handbook and User Guide, Published September 30th, 2014 and subsequent revisions, established by observations with survey-grade GNSS receivers. LOTS - 26.84 ACRES PARK - 2.16 ACRES OPEN SPACE - 3.24 ACRES RIGHT-OF-WAY - 11.74 ACRES TOTAL - 43.98 ACRES AREA SUMMARY PURPOSE TO CREATE 263 REMU LOTS 18 OPEN SPACE LOTS 4 PARK LOTS Exhibit C Post-Development Drainage Basins DYH II MW MW MW MW MW MW S S S S TP TP TP TP TP TP TP TP TP TP WV ESESESESESESESESESESESESESESESWW I II I III T CO CO CO CO COCO CO CO E27S E27SSTP MWMW MW MW MW MW MW MW I IWV EW EW GV1605036 4714.714100 S T HH HHHHHHHH HH HH HH SUB-BASIN 1 SUB-BASIN 7SUB-BASIN 6SUB-BASIN 2 SUB-BASIN 3 SUB-BASIN 4 SUB-BASIN 5 SUB-BASIN 8 SUB-BASIN 9 FIGURE NUMBER © PROJECT NO.DRAWN BY: DSGN. BY: APPR. BY: DATE: COPYRIGHT MORRISON-MAIERLE,2022 Plotted by cooper krause on Apr/4/2022 engineers surveyors planners scientists MorrisonMaierle 2880 Technology Blvd West Bozeman, MT 59718 406.587.0721 www.m-m.net N:\6787\002 - NW Crossing Ph II Pre Plat\ACAD\Exhibits\Storm-PreliminaryBasins+Ponds.dwg 6787.002 EX C NORTHWEST CROSSING SUBDIVISION- PHASE 2 BOZEMAN MONTANA PRELIMINARY STORM POND BASINS CPK CPK - 03/2022 100 200501000 SCALE IN FEET HARVEST P A R K W A YROSA WAYTWIN LAKESBAXTER LANE DAYSPRING AVE TOUCHSTONE DR WILDWOOD LANE DAYSPRING AVECOTTONWOOD ROADBAXTER DITCH OVERFLOW TO BAXTER DITCH NOTE: LAND NORTH OF THE CENTERLINE OF BAXTER LANE IS NOT YET ANNEXED INTO THE CITY. RIGHT-OF-WAY AND TEMPORARY STORM POND EASEMENTS NEGOTIATIONS ARE CURRENTLY UNDERWAY. FINAL STORM POND LOCATION WILL BE DESIGNED WITH DEVELOPMENT NORTH OF BAXTER LANE. UNDERGROUND DETENTION SYSTEM SURFACE RETENTION POND (TYP.) TEMPORARY RETENTION POND Appendix A NRCS Soils Report United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Gallatin County Area, Montana Northwest Crossing Subdivision Natural Resources Conservation Service February 10, 2020 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................11 Map Unit Descriptions.........................................................................................11 Gallatin County Area, Montana.......................................................................13 53B—Amsterdam silt loam, 0 to 4 percent slopes......................................13 448A—Hyalite-Beaverton complex, moderately wet, 0 to 2 percent slopes....................................................................................................14 451C—Quagle-Brodyk silt loams, 4 to 8 percent slopes.............................16 453B—Amsterdam-Quagle silt loams, 0 to 4 percent slopes......................18 457A—Turner loam, moderately wet, 0 to 2 percent slopes.......................20 509B—Enbar loam, 0 to 4 percent slopes...................................................22 510B—Meadowcreek loam, 0 to 4 percent slopes......................................23 537A—Lamoose silt loam, 0 to 2 percent slopes........................................24 References............................................................................................................27 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report 6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 7 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 8 9 Custom Soil Resource Report Soil Map 5059700505980050599005060000506010050602005060300506040050605005060600506070050608005060900506100050597005059800505990050600005060100506020050603005060400506050050606005060700506080050609005061000491100 491200 491300 491400 491500 491600 491700 491800 491900 492000 491100 491200 491300 491400 491500 491600 491700 491800 491900 492000 45° 42' 10'' N 111° 6' 55'' W45° 42' 10'' N111° 6' 6'' W45° 41' 25'' N 111° 6' 55'' W45° 41' 25'' N 111° 6' 6'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 12N WGS84 0 300 600 1200 1800 Feet 0 50 100 200 300 Meters Map Scale: 1:6,740 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Gallatin County Area, Montana Survey Area Data: Version 23, Sep 16, 2019 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Sep 10, 2012—Nov 12, 2016 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 10 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 53B Amsterdam silt loam, 0 to 4 percent slopes 34.1 18.0% 448A Hyalite-Beaverton complex, moderately wet, 0 to 2 percent slopes 32.2 17.0% 451C Quagle-Brodyk silt loams, 4 to 8 percent slopes 3.7 1.9% 453B Amsterdam-Quagle silt loams, 0 to 4 percent slopes 6.4 3.4% 457A Turner loam, moderately wet, 0 to 2 percent slopes 39.9 21.0% 509B Enbar loam, 0 to 4 percent slopes 2.9 1.5% 510B Meadowcreek loam, 0 to 4 percent slopes 51.3 27.0% 537A Lamoose silt loam, 0 to 2 percent slopes 19.3 10.2% Totals for Area of Interest 189.8 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas Custom Soil Resource Report 11 are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 12 Gallatin County Area, Montana 53B—Amsterdam silt loam, 0 to 4 percent slopes Map Unit Setting National map unit symbol: 56ws Elevation: 4,400 to 5,550 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 37 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: All areas are prime farmland Map Unit Composition Amsterdam and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Amsterdam Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Loess Typical profile A - 0 to 8 inches: silt loam Bw - 8 to 15 inches: silt loam Bk - 15 to 42 inches: silt loam 2C - 42 to 60 inches: very fine sandy loam Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 35 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.9 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Custom Soil Resource Report 13 Minor Components Quagle Percent of map unit: 5 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Limy (Ly) 15-19" p.z. (R044XS357MT) Hydric soil rating: No Blackdog Percent of map unit: 5 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No Bowery Percent of map unit: 3 percent Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No Meagher Percent of map unit: 2 percent Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No 448A—Hyalite-Beaverton complex, moderately wet, 0 to 2 percent slopes Map Unit Setting National map unit symbol: 56sq Elevation: 4,450 to 5,300 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 39 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: Farmland of local importance Map Unit Composition Hyalite and similar soils: 70 percent Beaverton and similar soils: 20 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 14 Description of Hyalite Setting Landform: Stream terraces, alluvial fans Down-slope shape: Linear Across-slope shape: Linear Parent material: Loamy alluvium Typical profile A - 0 to 5 inches: loam Bt1 - 5 to 9 inches: clay loam Bt2 - 9 to 17 inches: silty clay loam 2Bt3 - 17 to 26 inches: very cobbly sandy clay loam 3C - 26 to 60 inches: very cobbly loamy sand Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: About 48 to 96 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 5 percent Available water storage in profile: Low (about 4.4 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: C Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Description of Beaverton Setting Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile A - 0 to 5 inches: cobbly loam Bt - 5 to 21 inches: very gravelly clay loam Bk - 21 to 25 inches: very cobbly coarse sandy loam 2Bk - 25 to 60 inches: extremely cobbly loamy coarse sand Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: About 48 to 96 inches Frequency of flooding: None Custom Soil Resource Report 15 Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Low (about 3.7 inches) Interpretive groups Land capability classification (irrigated): 4s Land capability classification (nonirrigated): 6s Hydrologic Soil Group: B Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Minor Components Beaverton Percent of map unit: 5 percent Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT) Hydric soil rating: No Meadowcreek Percent of map unit: 5 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Subirrigated (Sb) 15-19" p.z. (R044XS359MT) Hydric soil rating: No 451C—Quagle-Brodyk silt loams, 4 to 8 percent slopes Map Unit Setting National map unit symbol: 56sy Elevation: 4,350 to 5,150 feet Mean annual precipitation: 14 to 18 inches Mean annual air temperature: 39 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: Farmland of statewide importance Map Unit Composition Quagle and similar soils: 70 percent Brodyk and similar soils: 20 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 16 Description of Quagle Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Silty calcareous loess Typical profile A - 0 to 6 inches: silt loam Bw - 6 to 9 inches: silt loam Bk - 9 to 60 inches: silt loam Properties and qualities Slope: 4 to 8 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 35 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.8 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Limy (Ly) 15-19" p.z. (R044XS357MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Description of Brodyk Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Silty calcareous loess Typical profile A - 0 to 6 inches: silt loam Bk1 - 6 to 30 inches: silt loam Bk2 - 30 to 60 inches: silt loam Properties and qualities Slope: 4 to 8 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Custom Soil Resource Report 17 Calcium carbonate, maximum in profile: 30 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.5 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Limy (Ly) 15-19" p.z. (R044XS357MT), Limy Grassland (R044BP804MT) Hydric soil rating: No Minor Components Amsterdam Percent of map unit: 8 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No Anceney Percent of map unit: 2 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty-Droughty (SiDr) 15-19" p.z. (R044XS690MT) Hydric soil rating: No 453B—Amsterdam-Quagle silt loams, 0 to 4 percent slopes Map Unit Setting National map unit symbol: 56t5 Elevation: 4,400 to 5,450 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 37 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: All areas are prime farmland Map Unit Composition Amsterdam and similar soils: 60 percent Quagle and similar soils: 30 percent Minor components: 10 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 18 Description of Amsterdam Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Loess Typical profile A - 0 to 8 inches: silt loam Bw - 8 to 15 inches: silt loam Bk - 15 to 42 inches: silt loam 2C - 42 to 60 inches: very fine sandy loam Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 35 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.9 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Description of Quagle Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Silty calcareous loess Typical profile A - 0 to 6 inches: silt loam Bw - 6 to 9 inches: silt loam Bk - 9 to 60 inches: silt loam Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Custom Soil Resource Report 19 Frequency of ponding: None Calcium carbonate, maximum in profile: 35 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: High (about 10.8 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Ecological site: Limy (Ly) 15-19" p.z. (R044XS357MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Minor Components Beanlake Percent of map unit: 6 percent Landform: Stream terraces, alluvial fans Down-slope shape: Linear Across-slope shape: Linear Ecological site: Limy (Ly) 15-19" p.z. (R044XS357MT) Hydric soil rating: No Meagher Percent of map unit: 4 percent Landform: Alluvial fans, stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No 457A—Turner loam, moderately wet, 0 to 2 percent slopes Map Unit Setting National map unit symbol: 56tb Elevation: 4,300 to 5,200 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 39 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: Prime farmland if irrigated Map Unit Composition Turner and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Custom Soil Resource Report 20 Description of Turner Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile A - 0 to 6 inches: loam Bt - 6 to 12 inches: clay loam Bk - 12 to 26 inches: clay loam 2C - 26 to 60 inches: very gravelly loamy sand Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: About 48 to 96 inches Frequency of flooding: None Frequency of ponding: None Calcium carbonate, maximum in profile: 15 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Low (about 5.4 inches) Interpretive groups Land capability classification (irrigated): 3e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT), Upland Grassland (R044BP818MT) Hydric soil rating: No Minor Components Turner Percent of map unit: 5 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No Beaverton Percent of map unit: 5 percent Landform: Stream terraces, alluvial fans Down-slope shape: Linear Across-slope shape: Linear Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT) Hydric soil rating: No Meadowcreek Percent of map unit: 5 percent Landform: Stream terraces Custom Soil Resource Report 21 Down-slope shape: Linear Across-slope shape: Linear Ecological site: Subirrigated (Sb) 15-19" p.z. (R044XS359MT) Hydric soil rating: No 509B—Enbar loam, 0 to 4 percent slopes Map Unit Setting National map unit symbol: 56vp Elevation: 4,400 to 6,000 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 37 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: All areas are prime farmland Map Unit Composition Enbar and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Enbar Setting Landform: Flood plains Down-slope shape: Linear Across-slope shape: Linear Parent material: Loamy alluvium Typical profile A - 0 to 22 inches: loam Cg - 22 to 49 inches: sandy loam 2C - 49 to 60 inches: very gravelly loamy sand Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat poorly drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: About 24 to 42 inches Frequency of flooding: Rare Frequency of ponding: None Calcium carbonate, maximum in profile: 10 percent Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0 mmhos/cm) Available water storage in profile: Moderate (about 8.8 inches) Interpretive groups Land capability classification (irrigated): 3w Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C Custom Soil Resource Report 22 Ecological site: Subirrigated (Sb) 15-19" p.z. (R044XS359MT), Bottomland (R044BP801MT) Hydric soil rating: No Minor Components Nythar Percent of map unit: 10 percent Landform: Flood plains Down-slope shape: Linear Across-slope shape: Linear Ecological site: Wet Meadow (WM) 15-19" p.z. (R044XS365MT) Hydric soil rating: Yes Straw Percent of map unit: 5 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Silty (Si) 15-19" p.z. (R044XS355MT) Hydric soil rating: No 510B—Meadowcreek loam, 0 to 4 percent slopes Map Unit Setting National map unit symbol: 56vt Elevation: 4,200 to 5,950 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 39 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: Prime farmland if irrigated Map Unit Composition Meadowcreek and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Meadowcreek Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile A - 0 to 11 inches: loam Bg - 11 to 25 inches: silt loam 2C - 25 to 60 inches: very gravelly sand Custom Soil Resource Report 23 Properties and qualities Slope: 0 to 4 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat poorly drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: About 24 to 42 inches Frequency of flooding: None Frequency of ponding: None Salinity, maximum in profile: Nonsaline to slightly saline (0.0 to 4.0 mmhos/cm) Available water storage in profile: Low (about 5.1 inches) Interpretive groups Land capability classification (irrigated): 2e Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: Subirrigated (Sb) 15-19" p.z. (R044XS359MT), Subirrigated Grassland (R044BP815MT) Hydric soil rating: No Minor Components Blossberg Percent of map unit: 10 percent Landform: Terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Wet Meadow (WM) 15-19" p.z. (R044XS365MT) Hydric soil rating: Yes Beaverton Percent of map unit: 5 percent Landform: Stream terraces, alluvial fans Down-slope shape: Linear Across-slope shape: Linear Ecological site: Shallow to Gravel (SwGr) 15-19" p.z. (R044XS354MT) Hydric soil rating: No 537A—Lamoose silt loam, 0 to 2 percent slopes Map Unit Setting National map unit symbol: 56wp Elevation: 4,000 to 5,000 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 39 to 45 degrees F Frost-free period: 90 to 110 days Farmland classification: Farmland of local importance Map Unit Composition Lamoose and similar soils: 85 percent Custom Soil Resource Report 24 Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Lamoose Setting Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: Alluvium Typical profile A - 0 to 9 inches: silt loam Bg - 9 to 27 inches: silt loam 2C - 27 to 60 inches: very gravelly loamy sand Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: About 12 to 24 inches Frequency of flooding: None Frequency of ponding: None Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 3.0 mmhos/cm) Available water storage in profile: Low (about 5.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 5w Hydrologic Soil Group: B/D Ecological site: Wet Meadow (WM) 9-14" p.z. (R044XS349MT), Subirrigated Grassland (R044BP815MT) Hydric soil rating: Yes Minor Components Bonebasin Percent of map unit: 10 percent Landform: Terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Wet Meadow (WM) 15-19" p.z. (R044XS365MT) Hydric soil rating: Yes Meadowcreek Percent of map unit: 5 percent Landform: Stream terraces Down-slope shape: Linear Across-slope shape: Linear Ecological site: Subirrigated (Sb) 9-14" p.z. (R044XS343MT) Hydric soil rating: No Custom Soil Resource Report 25 Custom Soil Resource Report 26 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 27 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 28 Appendix B Groundwater Data 5/24/2019 6/9/2019 6/17/2019 6/23/2019 7/1/2019 7/10/2019 7/19/2019 7/29/2019 8/6/2019 8/21/2019 9/5/2019 13 4.92 5.00 2.67 4.00 4.25 4.75 5.58 5.67 5.33 2.25 2.56 7 2.83 2.58 2.00 2.42 3.00 3.08 3.08 3.17 2.42 2.42 3.34 14 3.75 4.50 2.83 3.42 3.58 4.17 4.83 3.00 4.00 3.00 4.79 8 4.17 2.58 2.67 2.67 3.00 3.17 3.33 3.33 3.00 2.24 3.44 10 2.50 1.92 2.25 2.17 2.50 2.50 2.42 3.25 1.25 2.83 3.08 1 3.42 3.25 2.08 2.42 3.83 3.58 3.42 2.17 2.67 1.92 3.69 3 2.75 2.75 2.25 1.75 3.33 4.17 4.58 3.67 2.42 2.00 3.82 4 4.00 4.33 2.75 2.92 4.33 4.33 4.33 4.33 3.00 3.42 4.61 *NOTE: NorthWest Crossing Subdivision - Weekly Water Levels (FT) Well DATES Value in each cell is the measurement from the ground level at each monitoring well to the static water level in each well. 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 5/17/2019 5/24/2019 5/31/2019 6/7/2019 6/14/2019 6/21/2019 6/28/2019 7/5/2019 7/12/2019 7/19/2019 7/26/2019 8/2/2019 8/9/2019 8/16/2019 8/23/2019 8/30/2019 9/6/2019 9/13/2019 9/20/2019Groundwater depth (feet)Date NorthWest Crossing Groundwater Depth Well 1 Well 3 Well 4 Well 7 Well 8 Well 10 Well 13 Appendix C Preliminary Storm Water Calculations Hydrology Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Monday, Apr 4 2022 Phase 2- Pre-Development Hydrograph type = Rational Peak discharge (cfs) = 5.438 Storm frequency (yrs) = 10 Time interval (min) = 1 Drainage area (ac) = 43.400 Runoff coeff. (C) = 0.2 Rainfall Inten (in/hr) = 0.627 Tc by FAA (min) = 62 IDF Curve = COB IDF.IDF Rec limb factor = 1.00 Hydrograph Volume = 20,229 (cuft); 0.464 (acft) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 6.00 6.00 Q (cfs) Time (min) Runoff Hydrograph 10-yr frequency Runoff Hyd - Qp = 5.44 (cfs) FAA Formula Tc Worksheet Tc = 1.8(1.1 - C) x Flow length^0.5 / Watercourse slope^0.333 Hydraflow Express by Intelisolve Rational Phase 2- Pre-Development Description Flow length (ft) = 1650.00 Watercourse slope (%) = 1.20 Runoff coefficient (C) = 0.20 Time of Conc. (min) = 62 Hydrology Report Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.Monday, Apr 4 2022 Basin 1- Post-Development Detention Hydrograph type = Rational Peak discharge (cfs) = 22.92 Storm frequency (yrs) = 10 Time interval (min) = 1 Drainage area (ac) = 31.670 Runoff coeff. (C) = 0.64 Rainfall Inten (in/hr) = 1.131 Tc by FAA (min) = 25 IDF Curve = COB IDF.IDF Rec limb factor = 1.00 Hydrograph Volume = 34,374 (cuft); 0.789 (acft) 0 5 10 15 20 25 30 35 40 45 50 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (min) Runoff Hydrograph 10-yr frequency Runoff Hyd - Qp = 22.92 (cfs)Outflow Hyd *Req. Stor = 26,205 (cuft) * * Estimated FAA Formula Tc Worksheet Tc = 1.8(1.1 - C) x Flow length^0.5 / Watercourse slope^0.333 Hydraflow Express by Intelisolve Rational Basin 1- Post-Development Detention Description Flow length (ft) = 1200.00 Watercourse slope (%) = 1.50 Runoff coefficient (C) = 0.64 Time of Conc. (min) = 25 Appendix D Operation and Maintenance Manual Storm Water Management System Operation & Maintenance Manual Northwest Crossing Subdivision- Phase 2 Bozeman, Montana Prepared For: Williams Communities, LLC 21080 Centre Point Parkway Santa Clarita, CA 91350-2984 Prepared By: 2880 Technology Blvd. W. • PO Box 1113 • Bozeman, MT 59771 (406) 587-0721 • www.m-m.net Northwest Crossing- Phase 2 Storm Water Operation & Maintenance Manual 1 Site Data Location: Northwest Crossing Subdivision Tract 5 of Certificate of Survey No. 2552, located in the NE1/4 of Section 4, Township 2 South, Range 5 East, Principal Meridian Bozeman, Gallatin County, Montana Approximate WGS84 Reference Latitude: 45º41’47” N Approximate WGS84 Reference Longitude: 111º06’24” W Phase 2 lies in the north east corner of the property and encompasses about 44 acres. Responsible Party for Maintenance: For those storm water management system elements outside of dedicated public rights-of-way, the owner shall designate a qualified professional entity or individual to perform all monitoring. The name, address and telephone number of the entity or individual shall be provided to the City of Bozeman Public Works Department. The owner's representative shall be required to keep a log of all required inspections and maintenance required. The log shall be made available to the City of Bozeman Public Works Department for review as requested. Land Use & Site Area: The proposed Northwest Crossing Subdivision project is located in Bozeman, Gallatin County, Montana. Generally, the property is bordered by Baxter Lane to the north, Cottonwood Road to the east, Oak Street to the south, and Laurel Parkway to the west. Phase 2 of the Northwest Crossing subdivision is proposed to include about 358 residential units ranging from single family homes, duplexes and townhomes. Storm Water Management Systems: The proposed Northwest Crossing Subdivision development is to include a system of storm drainage inlets, piping, and surface storm water retention systems and underground detention systems. Phase 2 of the project area is divided into eight distinct major, post-development drainage basins which are shown in in Figure 1 on the following page. Northwest Crossing- Phase 2 Storm Water Operation & Maintenance Manual 2 Figure 1: Major Drainage Basins Northwest Crossing- Phase 2 Storm Water Operation & Maintenance Manual 3 Inspection & Maintenance Storm water facilities and permanent Best Management Practices (BMPs) must be inspected in accordance with this document. All documentation on scheduled inspections, times of inspections, maintenance completed, remedial actions taken to make repairs, and any modifications or reconstruction of the storm system shall be maintained on-site. Disposal of the accumulated sediment must be in accordance with all applicable local, state, and federal guidelines and regulations. If any drainage structure or outfall indicates the presence of petroleum, the petroleum material shall be removed and disposed of immediately in accordance with applicable regulations. Pavement Sweeping & Vacuuming: All paved areas shall be swept twice a year, scheduled in spring and fall. Inlets & Catch Basins All inlets and catch basins shall be inspected to ensure they have adequate sump capacity, hoods are in place, frames and grates are not damaged, and internal concrete and grout is intact. ❑ Inspect catch basins four times per year and following large storm events. ❑ Clean sump annually or whenever basin sump becomes filled with sediment to half its depth (0’-4 1/2”). If inspection indicates the presence of petroleum, the petroleum material shall be removed and disposed of immediately in accordance with applicable regulations. Storm Drain Manholes & Overflow Control Structures All storm drain manholes and overflow control structures shall be inspected to ensure manhole frames and covers are not damaged, inlet and outlet pipes are draining freely, and internal manhole concrete and grout is intact. ❑ Inspect structures annually and following large storm events. ❑ Clean structures as field determined. If inspection indicates the presence of petroleum, the petroleum material shall be removed and disposed of immediately in accordance with applicable regulations. Northwest Crossing- Phase 2 Storm Water Operation & Maintenance Manual 4 Piping All storm drain piping shall be inspected for any damage and/or blockages. ❑ Inspect piping annually and following large storm events. ❑ Length of pipes should be cleaned and flushed as field determined. Surface Retention System: Maintenance of the surface retention basin is also essential. General objectives of maintenance are to prevent clogging, standing water and the growth of weeds and wetland plants. This requires frequent unclogging of the outlets, inlets, and mowing. Cleaning out sediment with earth-moving equipment may also be necessary in 10 to 20 years. ❑ Inspect surface every three (3) months and following large storm events. ❑ Remove any accumulated trash. ❑ Sediment removal is to be provided as required. More frequent sediment removal via hand tools may reduce or eliminate the need for earth-moving equipment for sediment removal at a later date. If inspection indicates the presence of petroleum, the petroleum material shall be removed and disposed of immediately in accordance with applicable regulations. Housekeeping Operations Good housekeeping and material management reduces the risk of spills or other accidental exposure of materials and substances to storm water runoff. ❑ All materials stored on-site must be stored in a neat, orderly manner in their appropriate containers and, if possible, under a roof or other enclosure. ❑ Products shall be kept in their original containers with the original manufacturer’s label. ❑ Substances should not be mixed with one another unless recommended by the manufacturer. ❑ Whenever possible, all of a product will be used up before disposing of a container. ❑ Original materials labels and material safety data sheets (MSDS) shall be kept by the Owner. ❑ Petroleum products: ▪ All on-site vehicles and parking areas shall be monitored weekly for leaks and spills. Spills shall be cleaned immediately. ▪ Petroleum products shall be stored under cover and shall be in tightly sealed containers that are clearly labeled. ❑ Fertilizers: ▪ Fertilizers shall only be used in the minimum amounts as recommended by the manufacturer. ▪ The contents of any unused fertilizer shall be transferred to a clearly labeled, sealable plastic bin to avoid spillage. Northwest Crossing- Phase 2 Storm Water Operation & Maintenance Manual 5 ❑ Paints solvents. ▪ All paints and solvents shall be stored in original manufacturer’s containers in a covered location. ▪ The use of paints and solvents shall, whenever possible, be limited to service or storage bays. Where not possible, the work area shall be protected with impermeable drop clothes or tarps. At no point shall material be used in parking or access ways that are tributaries to the drainage system. Spill Control Practices ❑ Manufacturer's recommended methods shall be clearly posted for spill clean-up and hotel personnel shall be made aware of the procedures and the locations of cleanup information and supplies. ❑ Material and equipment necessary for spill clean-up will be kept on-site in a designated material storage area. Equipment will include, but not be limited to, brooms, dust pans, mops, rags, gloves, goggles, absorbent materials, sand, sawdust, and plastic & metal trash containers specifically kept and labeled for this purpose. ❑ All spills must be cleaned-up immediately after discovery. ❑ Spills of toxic or hazardous material must be reported to the appropriate state, local, or federal agency, as required by-law. Winter Maintenance Activities ❑ Snow plowing operations shall stockpile snow, ice and accumulated materials in areas where snow melt will flow into the on-site drainage systems, including drainage basins. ❑ During winter conditions sand use site-wide shall be applied to the minimum extent possible to maintain safe conditions and limit accumulations within the storm water management systems. ❑ The usage of sodium chloride or chloride containing materials for snow and ice removal is not recommended so as to avoid the introduction of salts to the storm water management system. Emergency Contacts PLEASE CALL 9-1-1 FOR ALL POTENTIAL EMERGENCIES City of Bozeman Fire Department: (406) 582-2350 City of Bozeman Police Department: (406) 582-2000