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HomeMy WebLinkAbout07 - Design Report - Baxter Square Phs 3 & 4 - Water, Sewer, Stormwater DESIGN REPORT WATER, SEWER & STORM WATER MANAGEMENT BAXTER SQUARE SUBDIVISION - PHASE 3 & 4 Prepared for: BAXTER SQUARE PARTNERS, L.L.C. 1174 Stoneridge Drive Bozeman, MT 59718 CAVU Development, LLC 13707 Camp Creek Road Manhattan, MT 59741 Prepared by: C & H Engineering and Surveying, Inc. 1091 Stoneridge Dr. Bozeman, MT 59718 (406) 5 87-1115 ' ' HAW A. Project Number: 07102 & 07103 u `�` ki July, 2007 INTRODUCTION Baxter Square Subdivision is proposed as a 102 lot residential subdivision. The development will consist primarily of townhouse clusters with the exception of two lots on which 8-plexes will be constructed. The property was annexed into the City of Bozeman as two separate parcels with zoning designations of R-3. The entire 18.1207 acre subdivision is located on the northern boundary of the City of Bozeman limits off of Baxter Lane approximately '/2 mile west of North 19`h Avenue. The property is surrounded by a mix of residential subdivisions and agricultural land. The development is situated in the East Half of the Southwest Quarter and the West Half of the Southeast Quarter of Section 35, Township 1 South, Range 5 East of P.M.M., Gallatin County, Montana. Phase 1 and 2 are nearly built out and there is also one single family residence and several outbuildings located on the property. The remainder of the property consists of horse pasture and hay fields. The topography is relatively uneven with a general slope to the north. Cattail Creek flows along the southern half of the western boundary of the subdivision. Phase 3 of the subdivision consists of 25 lots in the northeast quadrant of the project and Phase 4 consists of 24 lots in the northwest quadrant of the project. Phase 3 and 4 account for a total of 7.997 acres of the Baxter Square Subdivision. The project requires connection to the City of Bozeman water and sanitary sewer system. Access to Phase 3 and 4 will be provided directly from Sartain Street and Buckrake Avenue constructed with Phase 1 of the subdivision. Design Report-Page I of 15 WATER SYSTEM An analysis of the proposed water system was completed in the Phase 1 design report. The analysis indicated that the proposed system will provide adequate flow and pressure to meet fire flow demands at peak hour. SEWER SYSTEM Sewer service for Phase 3 and 4 of the subdivision will be provided via connection to the 8-inch main proposed in Phase 1 on Sartain Street. A new 8-inch main will be constructed northward on Hoover Way. The sewer will then continue east on G street and then south on Renee Way. The sewer will also be extended east on F street from Hoover Way. Service to each lot will be provided by 4-inch services constructed to 8 feet past the property line adjacent to public roads and 8 feet past the utility easement on private streets. Calculations provided in the Phase 1 design report show an 8-inch pipe at minimum slope to have adequate capacity to service the entire subdivision during peak periods. STORM WATER MANAGEMENT Summary Storm water run-off from Phase 3 of Baxter Square Subdivision will be directed to three storm water detention areas. Runoff from the south half of Phase 3 and 4 will be diverted to a storm water detention area proposed in the northwest corner of"Public Park 1". Runoff from the north half of Phase 4 and the north half of Phase 3 west of Renee Way will be diverted to the storm water detention area in the northwest corner of the subdivision. The runoff from the northeast quadrant of Phase 3 will be diverted into a storm water detention area on the west side of the intersection of G street and Renee Way. A map of the subdivision is enclosed in Appendix A, highlighting the drainage areas, inlets, storm sewers, and ponds. Design Report-Page 2 of 15 Composite runoff coefficients are calculated for each of the drainage areas using a runoff coefficient (C) of 0.90 for hard surfaces, a runoff coefficient (C) of 0.85 for house development, and a runoff coefficient of 0.30 for residential lawns/landscaping. DRAINAGE AREA 42 ANALYSIS Drainage Area#2 contains all of Phase 3 and Phase 4 south of the centerline of F Street and north of the centerline of Sartain Street. This area is shown on the Drainage Areas map enclosed in Appendix A. Drainage Area#2A Total Area =52,130 ft' = 1.1967 acres Roads (Pavement, C=0.90): Renee Way (282.4' x 18.5') = 5,225 ft'- F Street (391.7' x 18.5') = 7,229 ft'- Sartain Street (407.5' x 21.5') = 8,762 ft'- Total Area of Streets = 21,216 ft'- Residential: Total Area of Residential =27,746 ft'- From PUD Tabulation: 37.4% of residential area is buildings C=0.85) = 10,377 ft2 12.3% of residential is driveway C=0.90) = 3,413 ft' 50.3% of residential area is grass C=0.30) = 13,956 ft'- Additional Grass/Boulevard (Grass, C = 0.30): Area= 3,168 ft- Mean C = [(0.85 x 10,377 ft2)+(0.90 x 3,413 ft'-) + (0.30 x 13,956 ft'-) + (0.3 x 3,168) + (21,216 x 0.9)] / 52,130 ft2 = 0.693 Design Report-Page 3 of 15 Drainage Area 9213-1 Total Area = 65,911ft' = 1.513 acres Roads (Pavement, C = 0.90): Renee Street(294.4' x 26.5') = 7,800 ft2 F Street(279.F x 26.5' + 99.2'x14.5') = 8,833 ft2 Total area of streets = 16,633 ., Residential: Total area of residential = 0 ft2 Parkland/Open Space(Grass, C=0.30) = 49,277 ft2 Mean C = [(0.90 x 16,633 ft2) + (0.30 x 49,277 ft2)] /65,911 ft'- = 0.45 Drainage Area #2I3-2 Total Area = 19,879 ft' =0.4564 acres Roads (Pavement, C=0.90): Hoover Way (266.4' x 21.5') = 5,728 ft2 Sartain Street (435.5' x 24') = 10,452 ft'- Total Area of Streets = 16,180 ft2 Residential: Total Area of Residential = 0 ft2 Additional Grass/Boulevard (Grass, C = 0.30): Area= 3,699 ft2 Mean C = [+(0.90 x 16,180 ft2) + (0.30 x 3,699 ft2) / 19,879 ft'- =0.788 Design Report-Page 4 of 15 Drainage Area #2C Total Area =31,988 ft2 = 0.7343 acres Roads (Pavement, C=0.90): Hoover Way (266.4' x 21.5') = 2,343 ft'- Sartain Street (266.4' x 21.5') = 5,728 ft'- Total Area of Streets = 8,071 ft'- Residential: Total Area of Residential =20,325 ft'- From PUD Tabulation: 37.4% of residential area is buildings C=0.85) = 7,602 ftz 12.3% of residential is driveway C=0.90) = 2,500 ft2 50.3% of residential area is grass C=0.30) = 10,223 ft'- Additional Grass/Boulevard (Grass, C =0.30): Area= 3,592 ft'- Mean C = [(0.90 x 8,071 ft')+ (0.85 x 7,602 ft'-) + (0.90 x 2,500 ft'-)+ (0.3 x 10,223) + (0.3 x 3,592] / 31,988 ft'- = 0.63 Drainage Area #5 Total Area = 17,733 ft2 = 0.4071 acres Park= Additional Grass/Boulevard (Grass, C = 0.30): Area= 17,733 ft'- Mean C = 0.30 Drainage Area #2 (Overall) Total Area = 187,641 ft' =4.3076 acres Mean C = [(0.693 x 52,130 ft'-) + (0.45 x 65,911 ft'-) + (0.788 x 19,879) +(0.63 x 31,988)+ (0.3 x 17,733)] / 187,641 ft'- = 0.57 Design Report-Page 5 of 15 Storm Sewer#10 Storm Sewer#10 carries runoff from Drainage Area 2A under F Street to Storm Sewer#12 and on to Detention Pond#5. The flow anticipated from a 25-year storm event is calculated as follows: Time of Concentration Overland flow(177 ft @ 1.0%, C=0.20) =21.0 min.(see Figure I-1, Appendix A) Gutter flow(1082 ft @ 0.922% avg.slope) V=(1.486/n)R213S'" (n=0.013, A=1.24 ft, P=9.23, R'-'3=0.2623, S'/'-=0.096) V= 2.88 ft/s T= 1082 ft/2.88 ft/s/60s/min =6.26 min Total Time of Concentration = 27.26 minutes= (0.454 hours) For a 25-year storm event: I25= 0.78X-.64 = 0.78(0.454)-64 = 1.29 in/hr QS = CIA= 0.693(1.29 in/lu)(1.1967 acres) = 1.07 cfs *This method for calculating the time to concentration and runoff flow rate was used for the remaining storm sewer in Phase 3 and Phase 4. These calculations are shown in spreadsheet format in Figure A-2, Appendix A. Calculations are enclosed in Appendix A for a 15" PVC pipe at 0.70% slope. The 15-inch pipe will flow at a depth of 4.52 inches with a velocity of 3.43 ft/sec. Storm Sewer 911 Storm Sewer#11 carries storm water runoff from Drainage Area 2C under Hoover Way to Storm Sewer#12 and on to Detention Pond#5. Design Report-Page 6 of 15 Storm Sewer#11 (cont'd) Time of Concentration Overland flow(177 ft @ 1.5%, C=0.20) = 18.5 min.(see Figure I-1, Appendix A) Gutter flow(354 ft @ 1.0% avg.slope = 1.97 min. Total Time of Concentration= 20.47 min. = 0.3412 hrs. For a 25 year storm event: I25 = 0.78X-0.64 = 0.78(0.3412)-0.64 =1.55 in/hr Q25 = CIA= 0.63(1.55 in/hr)(0.7343 acres)= 0.717 cfs See spreadsheet, Figure A-2, Appendix A, for time to concentration and runoff flow rate calculations. Calculations are enclosed in Appendix A for a 15" PVC pipe at 1.0% slope. The 15-inch pipe will flow at a depth of 3.37 inches with a velocity of 3.47 ft/sec. Storm Sewer#12 Storm Sewer#12 carries storm water runoff from Drainage Area 213-1, 213-2, Storm Sewer#10, and Storm Sewer#11 to Detention Pond#5 in the northwest corner of Public Park 1. Drainage Area 213-1 =65,911 ft'- Drainage Area 213-2 = 19,879 ft'- Total Area = 85,790 ft'- = 1.9695 acres Time of Concentration The furthest point in the drainage area is located at the south end of Drainage Area#213-1 Overland flow(315 ft @ 1.5%, C=0.20) =26 min. (see Figure I-1, Appendix A) Gutter flow(626 ft @ 0.5% avg.slope) =4.92 min. Total Time of Concentration= 3092 min. = 0.5153 hrs. For a 25 year storm event: I25= 0.78X-0.64 =0.78(0.5153)-0-64 =1.19 ii-/hr Q25 =CIA= 0.53(1.19 in/hr)(1.9695 acres) = 1.24 cfs ' Design Report-Page 7 of 15 Calculations are enclosed in Appendix A for a 15" PVC pipe at 0.70% slope. The 15-inch pipe will flow at a depth of 4.89 inches with a velocity of 3.57 ft/sec. Detention Pond #5 Detention Pond#5 will detain the runoff from all of Drainage Area#2 at frill build out. The storage basin located in the detention pond can have a release rate of pre-development flow. The calculation for the pre-development time of concentration is enclosed on Figure I-1 in Appendix A. The release rate is calculated as follows: Time of Concentration(610.4 LF @ 1.15%, C=0.20)=41 min = 0.68 hours I,o = 0.64)C.61 = 0.64 (0.68)-.65 = 0.82 in/hr Q O= CIA =0.20 (0.82 in/hr)(4.3076 acres) = 0.710 cfs Release rate The maximum required storage is calculated on the following page by varying the storm duration and holding the release rate at 0.710 cfs and using a C of 0.57. Detention Pond #5 C = 0.57 A= 4.3076 acres release rate = 0.71 cfs Storm Storm Runoff Release Required length(min) Iength(hrs) Intensity Q(future) Volume Volume Storage 36 0.60 0.89 2.19 4730.9 1533.6 3197.3 37 0.62 0.88 2.15 4776.5 1576.2 3200.3 38 0.63 0.86 2.11 4821.3 1618.8 3202.5 39 0.65 0.85 2.08 4865.3 1661.4 3203.9 40 0.67 0.83 2.05 4908.6 1704.0 3204.6 41 0.68 0.82 2.01 4951.2 1746.6 3204.E 42 0.70 0.81 1.98 4993.2 1789.2 3204.0 43 0.72 0.79 1.95 5034.5 1831.8 3202.7 44 0.73 0.78 1.92 5075.1 1874.4 3200.7 45 0.75 0.77 1.89 5115.2 1917.0 3198.2 46 0.77 0.76 1.87 5154.7 1959.6 3195.1 The proposed pond has a mid-depth surface area of 2,515 ft'-. At a depth of 1.5 feet, the pond has a storage volume of 3,772 ft3. Design Report-Page 8 of 15 Pond #S Outlet Control Structure Sizing The outlet control structure for Detention Pond#5 needs to limit the release rate to the predevelopment runoff rate of 0.710 cfs. The slot width is sized using the following equation: Q = CLH3/2 Where:Q = Discharge(cfs) C = Weir Coefficient= 3.33 L=Horizontal Length(feet) H=Head (feet) L= (0.710 cfs)/(3.33 x 1.5112) = 0.116 feet= 1.39 inches The weir needs to be 1.39 inches wide in order to limit the release rate to 0.710 cfs. DRAINAGE AREA #3 ANALYSIS Drainage Area#3 includes all of Phase 3 and Phase 4 north of the centerline of F Street and west of the centerline of Renee Way. This area is shown on the Drainage Areas map enclosed in Appendix A. Drainage Area #3A Total Area =30,269 ft2 = 0.6949 acres Roads (Pavement, C=0.90): Hoover Way(246' x 21.5') = 5A9 ft2 Total Area of Streets = 5,289 ft2 Residential: Total Area of Residential = 22,224 ft2 From PUD Tabulation: 37.4% of residential area is buildings C=0.85) = 8,312 ft2 12.3% of residential is driveway C=0.90) = 2,734 ft2 50.3% of residential area is grass C=0.30) = 11,179 ft2 Additional Grass/Boulevard(Grass, C = 0.30): Area= 2,756 ft2 Mean C = [(0.90 x 5,289 ft2) + (0.85 x 8,312 ft2)+(0.90 x 2,734 ft2) + (0.3 x 11,179) + (0.3 x 2,756)] /30,269 ft2 =0.61 -- Design Report-Page 9 of 15 Drainage Area #313 Total Area =5,682 ft2 = 0.1304 acres Roads (Pavement, C=0.90): G Street = 5,289 ft2 Total Area of Streets = 5,289 ft Mean C = 0.90 Drainage Area #3C Total Area =85,526 ft2 = 1.9634 acres Roads (Pavement, C=0.90): F Street (378.2' x 18.5') =6,997 ft'- Renee Way (199.8' x 18.5') = 3,696 ft2 G Street (373' x 18.5') = 6,901 ft'- Hoover Way(219' x 21.5') =4,709 ft'- Total Area of Streets = 22,303 ft'- Residential: Total Area of Residential= 63,223 ft'- From PUD Tabulation: 37.4% of residential area is buildings C=0.85) =23,645 12.3% of residential is driveway C=0.90) = 7,776 ft2 50.3% of residential area is grass C=0.30) = 31,801 ft'- Mean C = [(0.90 x 22,303 ft'-) + (0.85 x 23,645 ft'-) + (0.90 x 7,776 ft'-) + (0.3 x 31,801 ft'-)] / 85,526 ft'- = 0.633 Drainage Area #3 (Overall) Total Area = 121,477 ft2 =2.7887 acres Mean C = [(0.61 x 30,269 ft'-) +(0.90 x 5,682 ft2) + (0.633 x 85,526)] / 121,477 ft2 = 0.64 Storm Sewer#13 Storm Sewer#13 carries storm water runoff from Drainage Area 3C under G Street to Storm Sewer#14 then on to Storm Sewer#15 and into Pond#6. Time of Concentration Overland flow(275 ft @ 1.0%, C=0.20) =26.5 min.(see Figure I-1, Appendix A) Gutter flow(559 ft @ 1.0% avg.slope) = 3.11 min. Total Time to Concentration=29.61 min. = 0.4935 hrs. Design Report-Page 10 of 15 For a 25 year storm event: I,5 = 0.78X-061 = 0.78(0.4935)-0.64 =1.22 in/hr Q25 = CIA= 0.633(1.22 in/hr)(1.9634 acres) = 1.52 cfs See spreadsheet, Figure A-2, Appendix A, for time to concentration and runoff flow rate calculations. Calculations are enclosed in Appendix A for a 15" PVC pipe at 0.40% slope. The 15-inch pipe will flow at a depth of 6.34 inches with a velocity of 3.08 ft/sec. Storm Sewer#14 Storm Sewer#14 carries runoff from Drainage Areas 3B and 3C to Storm Sewer#15 and then into Pond#6. Runoff flow rate calculations are shown below. Drainage Area 3B = 5,682 Drainage Area 3C = 85,526 Total Area = 91,208 ft'-= 2.094 acres Time of Concentration 29.61 min. (previously calculated time to reach Storm Sewer#13, see Figure A-2) Pipe flow(26 feet in 15" PVC at 0.40%) V = 3.17ft/s Time=26 ft/3.17 ft/s/60s/min = 0.14 min. Total Time of Concentration= 29.75 min. = 0.4958 his. For a 25 year storm event: 125 =0.78X"0.64 = 0.78(0.4958)"064=1.22 ii-/hr Q25 = CIA=0.65(1.22)2.094 = 1.66 cfs Calculations are enclosed in Appendix A for a 15" PVC pipe at 0.40% slope. The 15-inch pipe will flow at a depth of 6.87 inches with a velocity of 3.20 ft/sec. Storm Sewer#15 Storm Sewer#15 will carry runoff from Drainage Areas 3A, 3B, and 3C into Pond#6. Drainage Area 3A =30,269 Drainage Area 3B = 5,682 Drainage Area 3C = 85,526 Total Area = 121,477 ft'- =2.789 acres Design Report-Page 11 of 15 Time of Concentration 29.75 min. (previously calculated time to reach Storm Sewer#14, see Figure A-2) Pipe flow(48 feet in 15" PVC at 0.40%) V = 3.20 ft/s Time= 48 ft/3.20 ft/s/60s/min = 0.25 min. Total Time of Concentration= 30.0 min. = 0.50 hrs. For a 25 year storm event: I1-5 = 0.78X"0.64 = 0.78(0.50)-0-64 =1.22 in/hr Q25 = CIA= 0.64(1.22 in/hr)(2.789 acres) =2.17 cfs Calculations are enclosed in Appendix A for a 15" PVC pipe at 0.40% slope. The 15-inch pipe will flow at a depth of 7.77 inches with a velocity of 3.38 ft/sec. Retention Pond #6 Retention Pond#6 is located in the northwest corner of Phase 4. It will retain all of the runoff from Drainage Area 3 at full build out. The anticipated flow from a 10-yr, 2 hr. storm event is calculated as follows: Drainage Area 3 = 121,477 ft'-, Mean C = 0.64 (calculated above) 110 = 0.64X".65 = 0.64 (2)-.65= 0.408 in/hr Req'd Volume =tCIA= (2 hrs x 0.64 x 0.408 in/hr x 121,477 ft2)(l712") = 5,286.7 ft3 The proposed pond has a mid-depth surface area of 3,597 ft'-. At a depth of 1.5 feet,the pond has a storage volume of 5,396 ft3. DRAINAGE AREA #4 ANALYSIS Drainage Area#4 includes the portion of Phase 3 north of the centerline of F street and east of the centerline of Renee Way. This area is shown on the Drainage Areas map enclosed in Appendix A. Drainage Area#4A Total Area = 7,010 ft' = 0.1609 acres Roads (Pavement, C=0.90): Renee Way (214.4' x 18.5') = 3,966 ft'- Total Area of Streets = 3,966 ft'- Concrete Walk ( C=0.90 ): =445 ft'- Design Report-Page 12 of 15 Drainage Area #4A (cont'd) Grass ( C=0.30 ): =2,599 ft'- Mean C = [(0.90 x 3,966 ft2) + (0.90 x 445 ft'-)+ (0.30 x 2,599 ft2)] / 7,010 ft'- = 0.678 Storm Sewer#16 Storm Sewer#16 will carry runoff from Drainage Area#4A into Retention Pond #7. Time of Concentration Overland flow (152 ft @ 1.0%, C=0.20) = 18 min.(see Figure I-1, Appendix A) Gutter flow(211 ft @ 0.922% avg.slope) = 1.22 min. Total Time of Concentration= 19.22 min. =032 hrs. For a 25 year storm event: I25 =0.78X-0-64 = 0.78(0.32)-0-64=1.62 in/hr Q25 = CIA= 0.678(1.62 in/lu)(0.1609 acres) = 0.176 cfs See spreadsheet, Figure A-2, Appendix A, for time to concentration and runoff flow rate calculations. Calculations are enclosed in Appendix A for a 15" PVC pipe at 2.5% slope. The 15-inch pipe will flow at a depth of 2.20 inches with a velocity of 3.29 ft/sec. Retention Pond #7 Retention Pond#7 will retain all of the runoff from Drainage Area#4A at full build out. The anticipated flow from a 10-yr, 2 hr. storm event is calculated as follows: Drainage Area 4A = 7,010 ft2, Mean C = 0.678 (calculated above) I10 =0.64X--65 = 0.64 (2)-_65 = 0.408 in/hr Req'd Volume =tCIA= (2 hrs x 0.678 x 0.408 in/lu x 7,010 ft2)(1712")= 323 ft' The proposed pond has a mid-depth surface area of 269 ft2. At a depth of 1.5 feet, the pond has a storage volume of 403 ft3. Design Report-Page 13 of* 15 Drainage Area #413 Total Area =9,743 ft2 = 0.2237acres Roads (Pavement, C=0.90): 8-Plex Parking Lot: =4,463 ft'- Roof( C=0.85 }: = 3,381 ft'- Grass ( C=0.20 ): = 1,899 ft'- Mean C = [(0.90 x 4,463 ft'-) + (0.85 x 3,381 ft'-) + (0.20 x 1,899 ft'-)] /9,743 ft'- = 0.746 Retention Pond #8 Retention Pond#8 will retain all of the runoff from Drainage Area#4B at frill build out. The anticipated flow from a 10-yr, 2 hr. storm event is calculated as follows: Drainage Area 4B = 9,743 ft'-, Mean C =0.748 (calculated above) Ito=0.64X-.65 = 0.64 (2)-65= 0.408 in/hr Req'd Volume = tCIA= (2 Ins x 0.746 x 0.408 in/hr x 9,743 ft)(l712") =494 W The proposed pond has a mid-depth surface area of 356 ft'-. At a depth of 1.5 feet, the pond has a storage volume of 534 ft3. Drainage Area #4C Total Area = 8,152 ft2 =0.1871 acres Grass/Landscaping ( C=0.20 ): = 5,367 ft'- Roof( C=0.85 ): =2,785 ft'- Mean C = [(0.20 x 5,367 ft'-) + (0.85 x 2,785 ft'-)] / 8152 ft'- = 0.422 Design Report-Page 14 of 15 Retention Pond #9 Retention Pond#9 will retain all of the runoff from Drainage Area#4C at frill build out. The anticipated flow from a 10-yr, 2 hr. storm event is calculated as follows: Drainage Area 4C = 8,152 ft'-, Mean C = 0.422 Ito= 0.64X".65 = 0.64 (2)".65 = 0.408 unlhr Req'd Volume =tCIA = (2 lies x 0.422 x 0.408 in/hr x 8,152 ft2)(1712") = 234 ft3 The proposed pond has a mid-depth surface area of 347 ft'-. At a depth of 1.0 foot, the pond has a storage volume of 347 ft3. STREETS, CURB AND GUTTER, SIDEWALKS Access to Phase 3 and Phase 4 roads will be provided directly from Phase 1. Sartain Street, the only public street within Phase 3, was installed upon completion of Phase 1 with a street width of 33' from back of curb to back of curb, a 7.5'-wide boulevard and T-wide sidewalk on each side of the street within a 60' public right-of-way. Sartain Street is built to these same specifications in Phase 4 as well. Hoover Way, the only other public road within Phase 4, will be constructed with a street width of 33' from back of curb to back of curb, a 7.5'-wide boulevard and T-wide sidewalk on each side of the street within a 60' public right-of-way. Phase 3 and Phase 4 will both contain portions of F Street and G Street. Phase 3 will also include the stretch of Renee Way between Sartain Street and G Street. These private streets will be constructed with a street width of 29' from back of curb to back of curb, and a 4' sidewalk placed directly against the back of curb on both sides of the road, with the exception of the north side of G Street. The portions of F Street and Renee Way adjacent to Public Park 1 will be widened to a 37'-width to account for parking spaces along the north and east sides of the park. Pedestrian ramps will be constructed at all intersections providing handicap access to the sidewalks and public park. PAVEMENT DESIGN The standard road cross-section used for the interior roads in Phase 1 and 2 was modified to accommodate the existing soil conditions in Phase 3 and 4. In areas requiring a deeper fill section, 3 inches of asphalt, 6 inches of 1.5-inch minus gravel, and 24 inches of 6-inch minus "pit run" will be placed on top of a non-woven separation fabric and compacted subgrade. These areas include Hoover Way, F Street, G Street, and the north portion of Renee Way. The south portion of Renee Way will require less fill and will be constructed with 3 inches of asphalt, 6 inches of 1.5-inch minus gravel, and 15 inches of 6-inch minus "pit run"placed on top of geogrid, non-woven separation fabric and compacted subgrade. Design Report-Page 15 of 15 Appendix A BAXTER SQUARE SUBDIVISION PHASE 3 & 4 DRAINAOL= ARL=AS RETENTION POND #6 3g RETENTION POND #7 3,597 SQ. FT. ® MID DEPTH x 1.5' DEEP 269 SQ. FT ® MID DEPTH x 1.5' DEEP 3:1 SIDE SLOPE 3:1 SIDE SLOPE INLET #15 INLET #14 ----_,-�- - --w--�----_------INLET 16 -- - - - RETENTION POND #8 356 SQ. FT ® MID DEPTH x 1.5' DEEP STORM WATER INLET 13 3:1 SIDE SLOPE OPEN SPACE -" I N p. N •� N K N� o- rn 1 � � o r` o c w- v2 d-K B--I I N N - N N LOT 1 0 00 00 o n __, ,n orn ,M f M, ro v �LUI 3' 3,187 F� Jco JM J Jo 00 om J� o� O� Orn o� �,943 s ft � LOT 2 t _ l 2,683 S.F ( ` RETENTION POND #9 j I _ T I 229 SQ. FT 0 MID DEPTH x 1.0' DEEP 3,1300 S.F. 71 LLB„ - r`' 3:1 SIDE SLOPE e LOT q LOT 4 3,129 S.F 3,627 sq f' n Q. m � °i o o N ,,. M � �Q. ,n_ LOT 1 1 LOT 5 Yi N y N Q N N 9No r7 y Q M M y M y Q f 3, 42 sq ft 1,967 S.F, om o 0`9 o� o� oa, o� o� o� of TABULATED AREAS J J J J N J J rn j" J LOT 6 �� -- - - o42-sq-I W.S. AREA SQ FT 3,12- S E 1 + a LOT 9 I INLET 2 3,627 so (t 2A 52,130 LOT 7 -- _ GG'� 213-1 65,911 3,126 s.F. LOT 8 C 2B-2 19,879 i i �t� LOT �I LOT772q 3A 30,269 I 1,965 S..F. Jp�� � LOT 9 i +o� I 3,042 sq It { 3B 5,682 96a sJF t + UBLIC PARK 1 LOT 6 I 3C 85,526 lv a5 98,599 0C/Cs 3,042 sq ft 4A 7,010 .F 'f LOT 5 2n 4B 9,743 3,627 sq ft 4C 8,152 Z 29 F f \ 1 LOT 4 5 17,733 \ a 3,627 sq It a LOT 3 TOTAL 332,731 3,042 sq ft F. \ LOT 2 DETENTION POND #5� \ 3,042 sa fI 2,515 SQ FT(MID DEPTH)x1.5'; 44:1 SIDE SLOPE LOT 1 .F. e 4,797 sq ft c�- CID q Scale In Feet PUBLIC 100 0 100 PARK 2 30 0 30 17,198 5q rt Scale In Meters Engineering end Surveying Inc. 1091 Stoneridge Drive•Bozeman, MT 59718 Phone(406)587-1115•Fax(406]587-9768 www.chengineers.com•info@chengineers.com Sheet I Of #07102 & 07103 1200 140 S 1000 ° ° I 120 w r 800 100 z M �.. z w w z r 6 C}0 cr �z 80Ul z d U LQ cn c� v 60 d r ►_ o � o 2 d J J cr cc uj 200 r w 1 � 40 0 0 0 20 C 0 FIGURE I-1 TIME OF CONCENTRATION (Rational Formula) 28 1200 140 lo00 ° ° I 120 w °\ O I V) w i— eaa 1&0 Z M z w w �5 ta. i cr 2 Q u 600 80 x w r v L) J L w uj 40o I I 60 r � r- a z a � J cr 200 ui 40 0 0 U",q 0 20 C 0 r, FIGURE I: TIME OF CONCENTRATION (Rational Formula) } 28 1200 Tv-T !40 1000 ° ° 120 r o � w r 800 100 z r z w L w600 80 c� z dz w r v L o v � G � c 400 60 cr r ►_ 0 0 Z ,C7 7d a 200 > b 0 4 0 0 0 20 0 FIGURE ILL OF CONCENTRATIONT_(Rational Formula) 28 1200 140 1000 ° 120 uj o� o � � w F- 800 10O z w U� z H z 600 a 80 z zd w N o c.> J G w c 400 60 a F- ►_ 0 0 LLJ 200 40 0 a 0 20 C 0 �iQAlicl 6u� AA6A �C- FIGURE I-1 TIIyIE OF CONCEN,mATION_(Rational Formula) 28 " 1200 140 1000 ° Z�ll ° I 120 w °� o � L w 800 D 100 Z m � I z W — W z LAJ 600 U 80 z w � U o I L) J I o U. LIJ 400 - 60 O a I W c J J uj 20Q 40 0 0 _ 20 c 0 DA ItJA6t AACA #A FIGURE I-1 TIME OF CONCENTRATION (Rational Formula) 28 #07102 & #07103 tmp#47 BAXTER SQUARE PHASE 3 & 4 STORM SEWER #10 PIPE FLOW CALCULATIONS Manning Pipe Calculator Given Input Data: Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . Circular solving for . . . . . . . . . . . . . . . . . . . . . Depth of Flow Diameter . . . . . . . . . . . . . . . . . . . . . . . . 15.0000 in Flowrate . . . . . . . . . . . . . . . . . . . . . . . . 1.0700 cfs Slope . . . . . . . . . . . . . . . . . . . . . . . . 0.0070 ft/ft Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0130 Computed Results: Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5254 in Area . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2272 ft2 wetted Area . . . . . . . . . . . . . . . . . . . . . 0.3121 ft2 Wetted Perimeter . . . . . . . . . . . . . . . . 17.4446 in Perimeter . . . . . . . . . . . . . . . . . . . . . . . 47.1239 in velocity . . . . . . . . . . . . . . . . . . . . . . . . 3.4288 fps Hydraulic Radius . . . . . . . . . . . . . . . . 2.5760 in Percent Full . . . . . . . . . . . . . . . . . . . . 30.1695 Full flow Flowrate . . . . . . . . . . . . . . 5.4047 cfs Full flow velocity . . . . . . . . . . . . . . 4.4041 fps Critical Information Critical depth . . . . . . . . . . . . . . . . . . 4.8842 in Critical slope . . . . . . . . . . . . . . . . . 0.0052 ft/ft Critical velocity . . . . . . . . . . . . . . . 3.0859 fps Critical area . . . . . . . . . . . . . . . . . . . 0.3467 ft2 Critical perimeter . . . : * " * * ' . . . . . 18.2179 in Critical hydraulic radius . . . . . . . 2.7407 in Critical top width . . . . . . . . . . . . . . 14.0581 in specific energy . . . . . . . . . . . . . . . . . 0.5598 ft Minimum energy . . . . . . . . . . . . . . . . . . 0.6105 ft Froude number . . . . . . . . . . . . . . . . . . . 1.1591 Flow condition . . . . . . . . . . . . . . . . . . Supercritical Page 1 #07102 & #07103 tmp#48 BAXTER SQUARE PHASE 3 & 4 STORM SEWER #11 PIPE FLOW CALCULATIONS Manning Pipe Calculator Given Input Data: Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . Circular Solving for . . . . . . . . . . . . . . . . . . . . . Depth of Flow Diameter . . . . . . . . . . . . . . . . . . . . . . . . 15.0000 in Flowrate . . . . . . . . . . . . . . . . . . . . . . . . 0.7170 cfs Slope . . . . . . . . . . . . . . . . . . . . . . . . 0.0100 ft/ft Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0130 Computed Results: Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3745 in Area . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2272 ft2 wetted Area . . . . . . . . . . . . . . . . . . . . . 0.2066 ft2 wetted Perimeter . . . . . . . . . . . . . . . . 14.8252 in Perimeter . . . . . . . . . . . . . . . . . . . . . . . 47.1239 in velocity . . . . . . . . . . . . . . . . . . . . . . . . 3.4700 fps Hydraulic Radius . . . . . . . . . . . . . . . . 2.0070 in Percent Full . . . . . . . . . . . . . . . . . . . . 22.4965 Full flow Flowrate . . . . . . . . . . . . . . 6.4598 cfs Full flow velocity . . . . . . . . . . . . . . 5.2639 fps Critical Information Critical depth . . . . . . . . . . . . . . . . . . 3.9733 in Critical slope . . . . . . . . . . . . . . . . . 0.0052 ft/ft Critical velocity . . . . . . . . . . . . . . . 2.7550 fps Critical area . . . . . . . . . . . . . . . . . . . 0.2603 ft2 Critical perimeter . . . . . . . . . . . . . . 16.2186 in Critical hydraulic radius . . . . . . . 2.3107 in Critical top width . . . . . . . . . . . . . . 13.2381 in Specific energy . . . . . . . . . . . . . . . . . 0.4683 ft Minimum energy . . . . . . . . . . . . . . . . . . 0.4967 ft Froude number . . . . . . . . . . . . . . . . . . . 1.3750 Flow condition . . . . . . . . . . . . . . . . . . Supercritical Page 1 #07102 & #07103 tmp#49 BAXTER SQUARE PHASE 3 & 4 STORM SEWER #12 PIPE FLOW CALCULATIONS Manning Pipe Calculator Given Input Data: Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . Circular Solving for . . . . . . . . . . . . . . . . . . . . . Depth of Flow Diameter . . . . . . . . . . . . . . . . . . . . . . . . 15.0000 in Flowrate . . . . . . . . . . . . . . . . . . . . . . . . 1.2400 cfs slope . . . . . . . . . . . . . . . . . . . . . . . . 0.0070 ft/ft Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0130 computed Results: Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8862 in Area . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2272 ft2 wetted Area . . . . . . . . . . . . . . . . . . . . . 0.3469 ft2 wetted Perimeter . . . . . . . . . . . . . . . . 18.2222 in Perimeter . . . . . . . . . . . . . . . . . . . . . . . 47.1239 in velocity . . . . . . . . . . . . . . . . . . . . . . 3. 5742 fps Hydraulic Radius . . . . . . . . . . . . . . . . 2.7416 in Percent Full . . . . . . . . . . . . . . . . . . . . 32.5743 Full flow Flowrate . . . . . . . . . . . . . . 5.4047 cfs Full flow velocity . . . . . . . . . . . . . . 4.4041 fps critical Information Critical depth . . . . . . . . . . . . . . . . . . 5.2717 in critical slope . . . . . . . . . . . . . . . . . . 0.0052 ft/ft Critical velocity . . . . . . . . . . . . . . . 3.2213 fps Critical area . . . . . . . . . . . . . . . . . . . 0.3849 ft2 critical perimeter . . . . . . . . . . . . . . 19.0371 in Critical hydraulic radius . . . . . . . 2.9118 in Critical top width . . . . . . . . . . . . . . 14.3227 in specific energy . . . . . . . . . . . . . . . . . 0.6057 ft Minimum energy . . . . . . . . . . . . . . . . . . 0.6590 ft Froude number . . . . . . . . . . . . . . . . . . . 1.1580 Flow condition . . . . . . . . . . . . . . . . . . supercritical Page 1 #07102 & #07103 tmp#50 BAXTER SQUARE PHASE 3 & 4 STORM SEWER #13 PIPE FLOW CALCULATIONS Manning Pipe Calculator Given Input Data: Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . Circular Solving for . . . . . . . . . . . . . . . . . . . . . Depth of Flow Diameter . . . . . . . . . . . . . . . . . . . . . . . . 15.0000 in Flowrate . . . . . . . . . . . . . . . . . . . . . . . . 1.5200 cfs slope . . . . . . . . . . . . . . . . . . . . . . . . 0.0040 ft/ft Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0130 Computed Results: Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3361 in Area . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2272 ft2 wetted Area . . . . . . . . . . . . . . . . . . . . . 0.4928 ft2 wetted Perimeter . . . . . . . . . . . . . . . . 21.2247 in Perimeter . . . . . . . . . . . . . . . . . . . . . . . 47.1239 in velocity . . . . . . . . . . . . . . . . . . . . . . . . 3.0842 fps Hydraulic Radius . . . . . . . . . . . . . . . . 3.3437 in Percent Full . . . . . . . . . . . . . . . . . . . . 42.2407 Full flow Flowrate . . . . . . . . . . . . . . 4.0855 cfs Full flow velocity . . . . . . . . . . . . . . 3.3292 fps Critical Information Critical depth . . . . . . . . . . . . . . . . . . 5.8597 in Critical slope . . . . . . . . . . . . . . . . . 0.0053 ft/ft Critical velocity . . . . . . . . . . . . . . . 3.4226 fps critical area . . . . . . . . . . . . . . . . . . . 0.4441 ft2 Critical perimeter . . . . . . . . . . . . . . 20.2547 in Critical hydraulic radius . . . . . . . 3.1573 in Critical top width . . . . . . . . . . . . . . 14.6369 in Specific energy . . . . . . . . . . . . . . . . . 0.6758 ft Minimum energy . . . . . . . . . . . . . . . . . . 0.7325 ft Froude number . . . . . . . . . . . . . . . . . . . 0.8607 Flow condition . . . . . . . . . . . . . . . . . . Subcritical Page 1 #07102 & 07103 tmp#51 BAXTER SQUARE PHASE 3 & 4 STORM SEWER #14 PIPE FLOW CALCULATIONS Manning Pipe Calculator Given Input Data: shape . . . . . . . . . . . . . . . . . . . . . . . . . . . Circular Solving for . . . . . . . . . . . . . . . . . . . . . Depth of Flow Diameter . . . . . . . . . . . . . . . . . . . . . . . . 15.0000 in Flowrate . . . . . . . . . . . . . . . . . . . . . . . . 1.6600 cfs slope . . . . . . . . . . . . . . . . . . . . . . . . 0.0040 ft/ft Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0130 Computed Results: Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6560 in Area . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2272 ft2 wetted Area . . . . . . . . . . . . . . . . . . . . . 0.5259 ft2 wetted Perimeter . . . . . . . . . . . . . . . . 21.8704 in Perimeter . . . . . . . . . . . . . . . . . . . . . . . 47.1239 in velocity . . . . . . . . . . . . . . . . . . . . . . 3.1567 fps Hydraulic Radius . . . . . . . . . . . . . . . . 3.4624 in Percent Full . . . . . . . . . . . . . . . . . . . . 44.3733 Full flow Flowrate . . . . . . . . . . . . . . 4.0855 cfs Full flow velocity . . . . . . . . . . . . . . 3.3292 fps Critical Information critical depth . . . . . . . . . . . . . . . . . . 6.1348 in Critical slope . . . . . . . . . . . . . . . . . . 0.0054 ft/ft Critical velocity . . . . . . . . . . . . . . . 3.5157 fps Critical area . . . . . . . . . . . . . . . . . . . 0.4722 ft2 Critical perimeter . . . . . . . . . . . . . . 20.8162 in Critical hydraulic radius . . . . . . . 3.2663 in Critical top width . . . . . . . . . . . . . . 14.7494 in specific energy . . . . . . . . . . . . . . . . . 0.7095 ft Minimum energy . . . . . . . . . . . . . . . . . . 0.7669 ft Froude number . . . . . . . . . . . . . . . . . . . 0.8553 Flow condition . . . . . . . . . . . . . . . . . . Subcritical Page 1 #07102 & #07103 tmp#52 BAXTER SQUARE PHASE 3 & 4 STORM SEWER #15 PIPE FLOW CALCULATIONS Manning Pipe Calculator Given Input Data: Shape . . . . . . . . . . . . . . . . . . . . . . . Circular Solving for . . . . . . . . . . . . . . . . . . . . . Depth of Flow Diameter . . . . . . . . . . . . . . . . . . . . . . . . 15.0000 in Flowrate . . . . . . . . . . . . . . . . . . . . . . . . 2.1700 cfs slope . . . . . . . . . . . . . . . . . . . . . . . . 0.0040 ft/ft Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0130 Computed Results: Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7740 in Area . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2272 ft2 wetted Area . . . . . . . . . . . . . . . . . . . . . 0.6421 ft2 Wetted Perimeter . . . . . . . . . . . . . . . . 24.1100 in Perimeter . . . . . . . . . . . . . . . . . . . . . . . 47.1239 in velocity . . . . . . . . . . . . . . . . . . . . . . . . 3.3794 fps Hydraulic Radius . . . . . . . . . . . . . . . . 3.8352 in Percent Full . . . . . . . . . . . . . . . . . . . . 51.8264 Full flow Flowrate . . . . . . . . . . . . . . 4.0855 cfs Full flow velocity . . . . . . . . . . . . . . 3.3292 fps critical Information Critical depth . . . . . . . . . . . . . . . . . . 7.0558 in Critical slope . . . . . . . . . . . . . . . . . . 0.0056 ft/ft Critical velocity . . . . . . . . . . . . . . . 3.8248 fps critical area . . . . . . . . . . . . . . . . . . . 0.5674 ft2 Critical perimeter . . . . . . . . . . . . . . 22.6731 in Critical hydraulic radius . . . . . . . 3.6033 in Critical top width . . . . . . . . . . . . . . 14.9737 in specific energy . . . . . . . . . . . . . . . . . 0.8253 ft Minimum energy . . . . . . . . . . . . . . . . . . 0.8820 ft Froude number . . . . . . . . . . . . . . . . . . . 0.8313 Flow condition . . . . . . . . . . . . . . . . . . Subcritical Page 1 � > � ' � tmp#54 � #07IO2 8 #07I03 8AXTER SQUARE PHASE ] & 4 STORM SEWER #16 � PIPE FLOW CALCULATIONS � Manning Pipe calculator ( Given Input Data: � Shape . . , , . . . . . . . . ' . . . . . . . . . . . . . . Circular Solving for . . . . . . . ' . . . . . . . . . . . . . Depth of Flow Diameter ' ' . . . . . . . , . . . . . . . . . ' . . . . I5.0000 in � Flmwrate . . . . . . . , . . . . . . . ' . . . . . . . , 0,1760 cfs � , Slope . . . . . . ' . . . , . . . . . . . . . . . . . . . . 0.0350 ft/ft manning's n . . . . . . . ' . . . . . . . . . . . . . 0.0130 computed Results: � Depth . . . . . . . . . . ' . . . . . . . . . . . . . . . . 1,3692 in Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2272 ft2 wetted Area , . . . . . . ' . . . . , . . . . . . . . 0.0559 ft2 Wetted Perimeter . , . . . . . . . . . . . . . . 9.2077 in � Perimeter . . . . . . . . . . . . . . . . . . . . . . . 47.1239 in Velocity . . . . . . . . . . . . . , . . . . . . . . . . 3.1510 fps Hydraulic Radius . . . . . . . . . . , . . . . . 0.8735 in Percent Full . . . . . . . . . . . . . . . . . . . , 9.1282 % � Full flow Flnwrate . . . . , . . . . . . . . . I0.2I38 cfs Full flow velocity . . . . ' ' . . . . . . . . 8.3230 fps critical Information | critical depth . . , . , . . . . . . . . , . . . . I.94I3 in critical slope . . . . . . . . . . . . . . . . . . 0.0058 ft/ft critical velocity . . . . . , . . . . . . . . . 1.8897 fps Critical area . . ' . . . . . . . ' ' . . . . . . . 0.093I ft2 | critical perimeter ' . . , . . . . . ' . . . . I1.0399 in � critical hydraulic radius . . ' , . . . 1.2I48 in critical top width , . . . . . . . . ' . . ' ' I0.0688 in specific energy . . . . . . . . ' . . . , . . . . 0.2684 ft � Minimum energy . . . . . . . . . . . . . . . . . . 0.2427 ft ' Froude number . . . . . . ' . . . . , . . . . . . . 1.9945 Flow condition . . . . ' . . . . . . . . . . . . . Supercritical E 0 () (1) CO U) CO U) U) U) w w w w w w w w 0 >- >- >- 0 0) C04) IC-) 4Q U? E m N CY) m Cl) CN co m 0 CN "It 0) co (0 C-4 CM CO 3 r- 't m ro� CO IN ce) co co co CY) m co 0) LO 00 CO CO 6 M P� (P 6 t'' o 0 (q CO 0 U N cq C) N LO (D (0 (D a) Cn 3. N9� NLO co 11 P- 00 co 00 N (D LO N U') 'o LO LO OD m CY) 00m I-- (0 N to rn Q0 co — N 0 0 0 (,0 It CM CO LL LL U- CD ry, z � w LU w D D OD 04 r- Ln 't a) Ln r 0 0 0 (0 M N M LO N o o o c 0J z z z 4+ CY) cr) cr) Cl) rl- > �2 cq NC� C� On O� C9 — CN N 04 04 N N It It It I'll It It I�t �2 �2 �2 �2 �2 �2 �2 r 6 6 6 C; 6 6 C5 m CY) (n co m co m N " N N " " N a) CY) CT) 0) 0) a) a) N N N co �2 �2 �2 M_ M_�2 �2 M O q q q 0 C) 0 0 N 0 0 0 0 0 0 C14 CY) LO 0 0 0 U') 0 CF) U) (0 -'r Ln n n oo n v NAE, 00 (0 E 04 " " N " N NN " NN 0 0 0 0 0 3: 0 0 0 0 0 0 -i m LL 0 04 0 Ln LO m > CL O O O O O z 0 0 0 0 0 w 0 o U) < )a z w = a. o (4 > � C 0 LU 2 co cn w < m-,a 0 _j 1) S Ln I- U) Z U-) cq 0 C) > t-- LO C\i r- (D r-- U) N m (0 N M N ;t U) -J W 0 (1) < C� < co N