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HomeMy WebLinkAboutCorrespondence - 10/14/20255265 Ronald Reagan Blvd., Suite 210 Johnstown, CO 80534 970.800.3300 • GallowayUS.com Memorandum HFH072_DR_Compliance-LTR.docx Page 1 of 2 To: City of Fort Collins Stormwater Utility From: Herman Feissner, P.E. Galloway & Company, LLC Date: October 14th, 2025 Re: Bloom Sojourn (Lot 1, Bloom Filing 9) | Drainage Compliance Letter (PDP) Introduction Bloom Sojourn (Site), Lot 1 of Bloom Filing 9 (F9), is generally located south of Donella Drive and east of proposed detention Pond G1. Lot 1 will be developed as a new concept brick- and-mortar restaurant incorporating food trucks. The proposed site improvements include the building, parking, common areas for patrons, landscaping, and site-specific wet and dry utilities. The backbone infrastructure is being designed and constructed with F9, which was recently submitted (2nd BDR, Galloway & Company, LLC) to the City of Fort Collins (CoFC) on October 1st, 2025. The following Drainage Compliance Letter provides supporting preliminary drainage design narrative and calculations (see attached) demonstrating compliance with the larger Bloom Filing 9 (Bloom Commercial) project drainage design in (3) – three key areas: Land Use Compliance, Storm Drain Infrastructure, and Water Quality. Land Use Compliance - Percent Imperviousness Lot 1 has been divided among (9) – nine Rational Method basins. The subset of basins (4.54- ac) most directly associated with the site and include G1.7, G1.8b, G1.10b, G1.11, G1.12, G1.13, and G1.14. Basins G1.8a and G1.10a are a part of Tract A which is a future hotel site to the north of Sojourn that will not be developed with this work. A future submittal will include interim off-site flows in the site-specific drainage design calculations. Several basins around the periphery were also included in this work for estimating the preliminary Low Impact Development (LID) facility volume tributary area (5.16-ac) G1.15, G1.16, and G1.17. The inclusion is largely driven by the F9 storm drain layout. Basin G1.9 (F9 – Pond G1) was not revised as apart of this current work. The above-mentioned basins are situated within SWMM Basin G1 (±32.0-ac, imp.=80%) of F9. The Sojourn basins have an estimated imperviousness of ±68.3%. This is less than 80%; therefore, detention Pond G1 should function as it was designed and present in the F9 work. Refer to the attached Rational Method Calculations for preliminary 2- and 100-year developed runoff estimates. Sheet C10.0, Drainage Plan, is also attached. The ‘mustard- colored’ basins are specific to this work while the grey-shaded basins are included for reference as they were submitted with the F9 Drainage Plan, which is also attached.. Storm Drain Infrastructure The design and construction of storm drain infrastructure shown on the Sojourn PDP construction documents, specifically sheet C5.0, Utility Plan, is split between the Site and F9. Bloom Filing 1 01/31/2025 HFH072_DR_Compliance-LTR.docx Galloway & Company, Inc. Page 2 of 2 Sheet C5.0 identifies which storm drain infrastructure will be constructed with F9 and Sojourn. For example, the proposed storm drain system and Type ‘R ‘Curb Inlets within the adjacent Right-of-Way bordering the South and East limits of Lot 1 will be constructed with F9. Alternatively, the proposed storm drain system and associated inlets in basin G1.8b will be constructed with Sojourn. Water Quality Compliance The Bloom Filing 9 drainage design work included estimated Water Quality Capture Volume (WQCV) and LID requirements for Lot 1 based on Section 2.3.7 Low Impact Development (FCSCM), “75% of all newly added or modified impervious area must be treated by LID technologies”. Specifically, the estimated (i.e., based on proposed land uses) newly added impervious area in SWMM Basin G1 outside of Filing 3, which provides local LID, was divided into LID technologies associated with each Lot/Tract (e.g., Tract A, Lot1, etc.) and WQCV associated with the roadway sections. The WQCV was added to the estimated 100-year storage volume in Pond G1. Ideally, the basins mentioned above comprising the 5.16-ac tributary and 3.52-ac of newly added impervious area can be routed to the proposed Rain Garden (RG) in Basin G1.10b. The minimum required design volume for this tributary area at ±68.3% impervious is ±4,009 ft3; the proposed preliminary RG provides ±4,733 ft3 at 12-inch deep. Alternatives to the RG we have considered include an ADS StormTech system in basin G1.10b, Grass Buffers in basins G1.12 and G1.13, and high flow rate bioretention systems such as the Filterra Bioretention System in basins G1.7 and G1.13.Our final direction and design will be provided with final design documents. Conclusion The proposed Sojourn development within Lot 1 of Bloom Filing 9 generally complies with the Final Drainage design presented with the Bloom Filing 9 design documents (2nd BDR). Sincerely, GALLOWAY & COMPANY, LLC Herman Feissner, P.E. Technical Project Manager HermanFeissner@GallowayUS.com Subdivision:Bloom Filing 9 Project Name: Bloom Sojourn Location:CO, Fort Collins Project No.: Calculated By: HHF Checked By: HHF INPUT User Input Date: 10/15/25 OUTPUT Calculated Value Single-Family Alley-Loaded SF Duplex/AttachedMulti-Family 95%5%100% G1.7 0.52 95 0.33 61 15 0.18 5 95 0.00 0 0.67 G1.8a 1.07 95 0.00 0 15 0.84 12 95 0.23 20 0.32 G1.8b 1.06 95 0.92 82 15 0.15 2 95 0.00 0 0.84 G1.9 2.44 95 0.00 0 15 1.55 10 95 0.89 35 0.44 G1.10a 0.18 95 0.00 0 15 0.11 10 95 0.07 35 0.44 G1.10b 1.30 95 0.98 71 15 0.33 4 95 0.00 0 0.75 G1.11 0.26 95 0.00 0 15 0.00 0 95 0.26 95 0.95 G1.12 0.51 95 0.19 35 15 0.32 9 95 0.00 0 0.45 G1.13 0.59 95 0.35 56 15 0.24 6 95 0.00 0 0.62 G1.14 0.29 95 0.14 45 15 0.15 8 95 0.00 0 0.53 G1.15 0.38 95 0.28 70 15 0.10 4 95 0.00 0 0.74 G1.16 0.12 95 0.08 67 15 0.04 4 95 0.00 0 0.71 G1.17 0.12 95 0.08 67 15 0.03 4 95 0.00 0 0.71 SOJOURN PROJECT SITE (approx.) 4.54 Newly Added Imp. Area, ac: 3.09 Trib. Area % Imp.: 68.1% SOJOURN LID Trib. Area, ac: 5.16 Newly Added Imp. Area, ac: 3.52 Trib. Area % Imp.: 68.3% COMPOSITE RUNOFF COEFFICIENTS HFH072 Area (ac)Basin ID Total Area (ac)Runoff Coefficient Area Weighted C2Runoff Coefficient Area (ac) Roofs, Ponds, and Gravel Runoff Coefficient Area (ac)Area Weighted Asphalt + Concrete Walks Lawns, Sandy Soil Area Weighted 10/15/2025 Subdivision:Bloom Filing 9 Project Name: Bloom Sojourn Location:CO, Fort Collins Project No.: Calculated By: HHF Checked By: HHF Date: 8/3/21 1 2 3 4 5 6 7 8 9 10 13 14 15 16 17 18 19 20 21 22 23 24 BASIN D.A. Hydrologic C2 C5 C100 L S Ti | 2-Year Ti | 100-Year L Calculated S Cv VEL.Tt COMP. Tc | 2-Year COMP. Tc | 100-Year TOTAL Urbanized Tc Tc | 2-Year Tc | 100-Year ID (AC) Soils Group Cf=1.00 Cf=1.00 Cf=1.25 (FT) (%) (MIN) (MIN) (FT) Slope, % (%) (FPS) (MIN) (MIN) (MIN) LENGTH(FT) (MIN) (MIN) (MIN) G1.7 0.52 B 0.67 0.67 0.83 39 2.00 4.0 2.5 344 0.57 0.57 20 1.5 3.8 7.8 6.3 383 12.1 7.8 6.3 G1.8a 1.07 B 0.32 0.32 0.40 155 2.00 14.4 13.0 0 0.00 20 0.0 0.0 14.4 13.0 155 10.9 10.9 10.9 G1.8b 1.06 B 0.84 0.84 1.00 114 2.10 4.1 1.6 19 0.53 0.53 20 1.4 0.2 4.3 1.8 133 10.7 5.0 5.0 G1.9 2.44 B 0.44 0.44 0.55 20 1.90 4.4 3.7 210 1.57 1.50 20 2.5 1.4 5.8 5.1 230 11.3 5.8 5.1 G1.10a 0.18 B 0.44 0.44 0.55 93 2.00 9.4 7.8 0 0.00 20 0.0 0.0 9.4 7.8 93 10.5 9.4 7.8 G1.10b 1.30 B 0.75 0.75 0.94 85 2.80 4.3 2.0 123 0.87 0.87 20 1.9 1.1 5.4 3.1 207 11.2 5.4 5.0 G1.11 0.26 B 0.95 0.95 1.00 0 0.00 0.0 0.0 0 0.00 0.00 20 0.0 0.0 0.0 0.0 0 10.0 5.0 5.0 G1.12 0.51 B 0.45 0.45 0.56 139 2.40 10.8 8.9 45 2.00 2.00 15 2.1 0.4 11.1 9.3 184 11.0 11.0 9.3 G1.13 0.59 B 0.62 0.62 0.78 99 2.00 7.1 4.8 185 0.54 0.54 20 1.5 2.1 9.2 6.9 284 11.6 9.2 6.9 G1.14 0.29 B 0.53 0.53 0.66 22 2.00 4.0 3.0 229 0.62 0.62 20 1.6 2.4 6.4 5.5 250 11.4 6.4 5.5 G1.15 0.38 B 0.74 0.74 0.92 40 0.70 4.8 2.4 280 0.45 1.70 20 1.3 3.5 8.3 5.9 320 11.8 8.3 5.9 G1.16 0.12 B 0.71 0.71 0.89 20 1.70 2.7 1.5 60 11.67 0.20 20 6.8 0.1 2.9 1.6 80 10.4 5.0 5.0 G1.17 0.12 B 0.71 0.71 0.89 20 1.70 2.7 1.5 60 11.67 0.20 20 6.8 0.1 2.9 1.6 80 10.4 5.0 5.0 NOTES: Ti = (1.87*(1.1 - CCf)*(L)^0.5)/((S)^0.33), S in %Cv Tt=L/60V 2.5 Velocity V=Cv*S^0.5, S in ft/ft 5 Tc Check = 10+L/180 7 For urbanized basins a minimum Tc of 5.0 minutes is required.10 For non-urbanized basins a minimum Tc of 10.0 minutes is required 15 20 Cv 2.5 5 7 10 15 20 STANDARD FORM SF-2 TIME OF CONCENTRATION Paved Areas and Shallow Paved Swales DATA Type of Land Surface Heavy Meadow Tillage/Field Short Pasture and Lawns Nearly Bare Ground Grassed Waterway SUB-BASIN Tc CHECK HFH072 FINAL INITIAL/OVERLAND (Ti) TRAVEL TIME (URBANIZED BASINS)(Tt) Paved Areas and Shallow Paved Swales Type of Land Surface Heavy Meadow Tillage/Field Short Pasture and Lawns Grassed Waterway Nearly Bare Ground 10/15/2025 Project Name: Bloom Sojourn Subdivision:Bloom Filing 9 Project No.:HFH072 Location:CO, Fort Collins Calculated By: HHF Design Storm:Checked By: HHF Date: TRAVEL TIME STREET De s i g n P o i n t Ba s i n I D Ar e a ( A c ) Ru n o f f C o e f f . | C 2 Tc | 2 - Y e a r ( m i n ) C* A ( A c ) I ( i n / h r ) Q ( c f s ) Tc ( m i n ) C* A ( A c ) I ( i n / h r ) Q ( c f s ) Sl o p e ( % ) St r e e t F l o w ( c f s ) De s i g n F l o w ( c f s ) Sl o p e ( % ) Pi p e S i z e ( i n c h e s ) Le n g t h ( f t ) Ve l o c i t y ( f p s ) Tt ( m i n ) REMARKS G1.7 G1.7 0.52 0.67 7.8 0.35 2.49 0.9 G1.8a G1.8a 1.07 0.32 10.9 0.34 2.15 0.7 G1.8b G1.8b 1.06 0.84 5.0 0.89 2.85 2.5 G1.9 G1.9 2.44 0.44 5.8 1.08 2.74 3.0 G1.10a G1.10a 0.18 0.44 9.4 0.08 2.29 0.2 G1.10b G1.10b 1.30 0.75 5.4 0.98 2.80 2.7 G1.11 G1.11 0.26 0.95 5.0 0.25 2.85 0.7 G1.12 G1.12 0.51 0.45 11.0 0.23 2.14 0.5 G1.13 G1.13 0.59 0.62 9.2 0.37 2.32 0.8 G1.14 G1.14 0.29 0.53 6.4 0.15 2.67 0.4 G1.15 G1.15 0.38 0.74 8.3 0.28 2.42 0.7 G1.16 G1.16 0.12 0.71 5.0 0.08 2.85 0.2 G1.17 G1.17 0.12 0.71 5.0 0.08 2.85 0.2 DIRECT RUNOFF TOTAL RUNOFF STREET PIPE STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) 2-Year 8/3/21 10/15/2025 STANDARD FORM SF-3 STORM DRAINAGE SYSTEM DESIGN (RATIONAL METHOD PROCEDURE) Project Name: Bloom Sojourn Subdivision:Bloom Filing 9 Project No.:HFH072 Location:CO, Fort Collins Calculated By: HHF Design Storm: Checked By: HHF Date: TRAVEL TIME STREET De s i g n P o i n t Ba s i n I D Ar e a ( A c ) Ru n o f f C o e f f . | C 10 0 Tc | 1 0 0 - Y e a r ( m i n ) C* A ( A c ) I ( i n / h r ) Q ( c f s ) Tc ( m i n ) C* A ( A c ) I ( i n / h r ) Q ( c f s ) Sl o p e ( % ) St r e e t F l o w ( c f s ) De s i g n F l o w ( c f s ) Sl o p e ( % ) Pi p e S i z e ( i n c h e s ) Le n g t h ( f t ) Ve l o c i t y ( f p s ) Tt ( m i n ) REMARKS G1.7 G1.7 0.52 0.83 6.3 0.43 9.38 4.1 G1.8a G1.8a 1.07 0.40 10.9 0.43 7.51 3.2 G1.8b G1.8b 1.06 1.00 5.0 1.06 9.95 10.6 G1.9 G1.9 2.44 0.55 5.1 1.35 9.91 13.4 G1.10a G1.10a 0.18 0.55 7.8 0.10 8.69 0.9 G1.10b G1.10b 1.30 0.94 5.0 1.22 9.95 12.2 G1.11 G1.11 0.26 1.00 5.0 0.26 9.95 2.6 G1.12 G1.12 0.51 0.56 9.3 0.29 8.04 2.3 G1.13 G1.13 0.59 0.78 6.9 0.46 9.12 4.2 G1.14 G1.14 0.29 0.66 5.5 0.19 9.74 1.9 G1.15 G1.15 0.38 0.92 5.9 0.35 9.56 3.3 G1.16 G1.16 0.12 0.89 5.0 0.10 9.95 1.0 G1.17 G1.17 0.12 0.89 5.0 0.11 9.95 1.0 100-Year DIRECT RUNOFF TOTAL RUNOFF STREET 6/2/21 PIPE 10/15/2025 Sheet 1 of 2 Designer: Company: Date: Project: Location: 1. Basin Storage Volume A) Effective Imperviousness of Tributary Area, Ia Ia =68.3 % (100% if all paved and roofed areas upstream of rain garden) B) Tributary Area's Imperviousness Ratio (i = Ia/100)i = 0.683 C) Water Quality Capture Volume (WQCV) for a 12-hour Drain Time WQCV = 0.21 watershed inches (WQCV= 0.8 * (0.91* i3 - 1.19 * i2 + 0.78 * i) D) Contributing Watershed Area (including rain garden area) Area = 224,769 sq ft E) Water Quality Capture Volume (WQCV) Design Volume VWQCV =4,009 cu ft Vol = (WQCV / 12) * Area F) For Watersheds Outside of the Denver Region, Depth of d6 = in Average Runoff Producing Storm G) For Watersheds Outside of the Denver Region, VWQCV OTHER =cu ft Water Quality Capture Volume (WQCV) Design Volume H) User Input of Water Quality Capture Volume (WQCV) Design Volume VWQCV USER =cu ft (Only if a different WQCV Design Volume is desired) 2. Basin Geometry A) WQCV Depth (12-inch maximum)DWQCV =12.00 in B) Rain Garden Side Slopes (Z = 4 min., horiz. dist per unit vertical) Z = 4.00 ft / ft (Use "0" if rain garden has vertical walls) C) Mimimum Flat Surface Area AMin =3070 sq ft D) Actual Flat Surface Area AActual =3126 sq ft E) Area at Design Depth (Top Surface Area)ATop =6340 sq ft F) Rain Garden Total Volume VT=4,733 cu ft (VT= ((ATop + AActual) / 2) * Depth) 3. Growing Media 4. Underdrain System A) Are underdrains provided? B) Underdrain system orifice diameter for 12 hour drain time i) Distance From Lowest Elevation of the Storage y =ft Volume to the Center of the Orifice ii) Volume to Drain in 12 Hours Vol12 =cu ft iii) Orifice Diameter, 3/8" Minimum DO = in Design Procedure Form: Rain Garden (RG) Herman Feissner Galloway & Company, LLC October 14, 2025 Bloom Sojourn Fort Collins, CO UD-BMP (Version 3.07, March 2018) Choose One Choose One 18" Rain Garden Growing Media Other (Explain): YES NO HFH072_UD-BMP_v3.07.xlsm, RG 10/14/2025, 1:46 PM Sheet 2 of 2 Designer: Company: Date: Project: Location: 5. Impermeable Geomembrane Liner and Geotextile Separator Fabric A) Is an impermeable liner provided due to proximity of structures or groundwater contamination? 6. Inlet / Outlet Control A) Inlet Control 7. Vegetation 8. Irrigation A) Will the rain garden be irrigated? Notes: Design Procedure Form: Rain Garden (RG) Herman Feissner Galloway & Company, LLC October 14, 2025 Bloom Sojourn Fort Collins, CO Choose One Choose One Choose One Sheet Flow- No Energy Dissipation Required Concentrated Flow- Energy Dissipation Provided Plantings Seed (Plan for frequent weed control) Sand Grown or Other High Infiltration Sod Choose One YES NO YES NO HFH072_UD-BMP_v3.07.xlsm, RG 10/14/2025, 1:46 PM G1.3 G1.4 G-OS G1.1 G1.2 G1.15G1.7 G1.16 G1.17 H1 H2 G1.5 G1.12 H5 H6 G1.13 G1.14 G1.11 G1.8 G1.9 acres H1 0.80 1.00 0.61 acres H2 0.81 1.00 0.55 acres H 0.91 1.00 6.16 acres G1.2 0.95 1.00 1.36acres G1.3 0.95 1.00 2.29 acres G1.9 0.46 0.58 2.44 acres G1.10 0.85 1.00 1.00 acres G1.8 0.83 1.00 2.06 acres G1.7 0.63 0.79 0.56 acres G1.12 0.95 1.00 0.61 acres G1.13 0.94 1.00 0.69 acres G1.11 0.87 1.00 0.61 acres G1.4 0.95 1.00 0.23 acres G1.5 0.95 1.00 0.25 acres G1.6 0.95 1.00 0.39 acres G1.16 0.70 0.87 0.12 acres H5 0.62 0.78 0.35 acres G1.1 0.95 1.00 1.56 acres G1.15 0.73 0.91 0.38 acres G1 % IMP. 72.5 32.0 acres G % IMP. 90.0 19.6 DESIGN POINT OVERLAND FLOW DIRECTION (I.E., LANDSCAPING) DIRECT FLOW DIRECTION (I.E., PAVEMENT, CURB AND GUTTER) BASIN ID 2-YR RUNOFF COEFFICIENT BASIN AREA (ACRES) acres A1 0.05 0.35 2.50 A APPROXIMATE DETENTION POND OVERFLOW PATH 100-YR RUNOFF COEFFICIENT BASIN BOUNDARY (i.e., SWMM) A BASIN BOUNDARY (i.e., Rational Method) SWMM BASIN ID SWMM BASIN AREA (ACRES) acres A1 0.05 0.35 2.50 SWMM BASIN IMPERVIOUS (%) RATIONAL METHOD BASIN IDENTIFIER SWMM BASIN IDENTIFIER Know what's before you dig. PGS JEP DRAINAGE PLAN 67 C10.1 - - - - - - - - - - - - - - H: \ H \ H a r t f o r d H o m e s \ C O F o r t C o l l i n s H F H 7 3 - B l o o m C o m m e r c i a l \ 0 C I V \ 3 - C D \ F D P \ H F H 0 7 3 _ C 1 0 . 1 D r a i n a g e P l a n . d w g - He r m a n F e i s s n e r - 10 / 1 / 2 0 2 5 BL O O M F I L I N G N I N E FI N A L D E V E L O P M E N T P L A N FO R T C O L L I N S , C O THESE PLANS ARE AN INSTRUMENT OF SERVICE AND ARE THE PROPERTY OF GALLOWAY, AND MAY NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED WITHOUT THE WRITTEN CONSENT OF GALLOWAY. COPYRIGHTS AND INFRINGEMENTS WILL BE ENFORCED AND PROSECUTED. COPYRIGHT 5235 Ronald Reagan Blvd., Suite 200 Johnstown, CO 80534 970.800.3300 GallowayUS.com NOT F O R CON S T R U C T I O N #Date Issue / Description Init. Project No: Drawn By: Checked By: Date: HFH000073.20 10/01/2025 Sheet of 68 J1 J G1.16 G1.17 H3 H8 H5 H6 G1.13 G1.14 acres H7 0.72 0.89 5.31 acres H3 0.85 1.00 0.61 acres J1 0.68 0.85 0.80 acres H8 0.39 0.49 3.09 acres G1.14 0.75 0.94 0.32 acres J 0.82 1.00 6.85 acres0.87 acres G1.17 0.71 0.89 0.12 acres H6 0.63 0.78 0.36 acres H % IMP. 80.0 10.7 acres J % IMP. 80.0 6.9 DESIGN POINT OVERLAND FLOW DIRECTION (I.E., LANDSCAPING) DIRECT FLOW DIRECTION (I.E., PAVEMENT, CURB AND GUTTER) BASIN ID 2-YR RUNOFF COEFFICIENT BASIN AREA (ACRES) acres A1 0.05 0.35 2.50 A APPROXIMATE DETENTION POND OVERFLOW PATH 100-YR RUNOFF COEFFICIENT BASIN BOUNDARY (i.e., SWMM) A BASIN BOUNDARY (i.e., Rational Method) SWMM BASIN ID SWMM BASIN AREA (ACRES) acres A1 0.05 0.35 2.50 SWMM BASIN IMPERVIOUS (%) RATIONAL METHOD BASIN IDENTIFIER SWMM BASIN IDENTIFIER Know what's before you dig. PGS JEP DRAINAGE PLAN 68 C10.2 - - - - - - - - - - - - - - H: \ H \ H a r t f o r d H o m e s \ C O F o r t C o l l i n s H F H 7 3 - B l o o m C o m m e r c i a l \ 0 C I V \ 3 - C D \ F D P \ H F H 0 7 3 _ C 1 0 . 1 D r a i n a g e P l a n . d w g - He r m a n F e i s s n e r - 10 / 1 / 2 0 2 5 BL O O M F I L I N G N I N E FI N A L D E V E L O P M E N T P L A N FO R T C O L L I N S , C O THESE PLANS ARE AN INSTRUMENT OF SERVICE AND ARE THE PROPERTY OF GALLOWAY, AND MAY NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED WITHOUT THE WRITTEN CONSENT OF GALLOWAY. COPYRIGHTS AND INFRINGEMENTS WILL BE ENFORCED AND PROSECUTED. COPYRIGHT 5235 Ronald Reagan Blvd., Suite 200 Johnstown, CO 80534 970.800.3300 GallowayUS.com NOT F O R CON S T R U C T I O N #Date Issue / Description Init. Project No: Drawn By: Checked By: Date: HFH000073.20 10/01/2025 Sheet of 68 acres G1.9 0.46 0.58 2.44 acres G1.7 0.63 0.79 0.56 acres G1.12 0.45 0.56 0.51 acres G1.13 0.62 0.78 0.59 acres G1.14 0.53 0.66 0.29 acres G1.16 0.71 0.89 0.12 acres G1.17 0.71 0.89 0.12 acres G1.15 0.74 0.92 0.38 acres G1.8a 0.32 0.40 1.07 acres G1.8b 0.84 1.00 1.06 acres G1.10a 0.44 0.55 0.18 acres G1.10b 0.75 0.94 1.30 acres G1.11 0.95 1.00 0.26 G1.15 G1.7 G1.16 G1.17 G1.12 G1.13 G1.14 G1.11 G1.8b G1.9 G1.8aG1.10a G1.10b Know what's before you dig. PGS JEP DRAINAGE PLAN 18 C10.0 - - - - - - - - - - - - - - H: \ H \ H a r t f o r d H o m e s \ C O F o r t C o l l i n s H F H 7 3 - B l o o m C o m m e r c i a l \ 0 C I V \ 3 - C D \ S O J \ P D P \ H F H 0 7 2 _ C 1 0 . 0 D r a i n a g e P l a n P D P . d w g - He r m a n F e i s s n e r - 10 / 1 5 / 2 0 2 5 SO J O U R N PR E L I M I N A R Y D E V E L O P M E N T P L A N FO R T C O L L I N S , C O THESE PLANS ARE AN INSTRUMENT OF SERVICE AND ARE THE PROPERTY OF GALLOWAY, AND MAY NOT BE DUPLICATED, DISCLOSED, OR REPRODUCED WITHOUT THE WRITTEN CONSENT OF GALLOWAY. COPYRIGHTS AND INFRINGEMENTS WILL BE ENFORCED AND PROSECUTED. COPYRIGHT 5235 Ronald Reagan Blvd., Suite 200 Johnstown, CO 80534 970.800.3300 GallowayUS.com NOT F O R CON S T R U C T I O N #Date Issue / Description Init. Project No: Drawn By: Checked By: Date: HFH000072 10/15/2025 Sheet of 18 DESIGN POINT OVERLAND FLOW DIRECTION (I.E., LANDSCAPING) DIRECT FLOW DIRECTION (I.E., PAVEMENT, CURB AND GUTTER) BASIN ID 2-YR RUNOFF COEFFICIENT BASIN AREA (ACRES) acres A1 0.05 0.35 2.50 A APPROXIMATE DETENTION POND OVERFLOW PATH 100-YR RUNOFF COEFFICIENT BASIN BOUNDARY (i.e., Rational Method) BLOOM COMMERCIAL A BASIN BOUNDARY (i.e., Rational Method) BLOOM SOJOURN SWMM BASIN ID SWMM BASIN AREA (ACRES) acres A1 0.05 0.35 2.50 SWMM BASIN IMPERVIOUS (%) RATIONAL METHOD BASIN IDENTIFIER SWMM BASIN IDENTIFIER