HomeMy WebLinkAboutDrainage Reports - 09/01/2021City of Fort Collins Approved Plans
Approved by:
Date:
Dan Mogen
09/01/2021
Figure 1: Existing culvert prior to CDOT intersection improvements.
Figure 2: Location photograph of existing culvert.
8/11/2021
E PROSPECT RD
QUEST DR
FOX GROVE DRSMITHFIELD DR KIT DEN DR
Printed: 11/16/2020.
All floodplain boundaries
are approximate.
This information is based on the Federal Emergency Management
Agency (FEMA) Flood Insurance Rate Map (FIRM) and the City of
Fort Collins Master Drainageway Plans. This letter does not imply
that the referenced property will or will not be free from flooding or
damage. A property not in the Special Flood Hazard Area or in a
City Designated Floodplain may be damaged by a flood greater
than that predicted on the map or from a local drainage problem
not shown on the map. This map does not create liability on the
part of the City, or any officer or employee thereof, for any damage
that results from reliance on this information.
FEMA Flood Risk Map
Moderate Risk
May include:
- Areas of FEMA 500-year floodplain (FEMA Zone X-shaded).
- Areas of FEMA or City 100-year floodplain (sheet flow) with
average depths of less than 1 foot.
- Areas protected by levees from the 100-year flood.
Low Risk
Areas outside of FEMA and City mapped 100-year and 500-year
floodplains. Local drainage problems may still exist.
FEMA Flood Fringe - May Include:
- Areas of FEMA 100-year floodplain (FEMA Zones A, AE, AO, and AH)
- Areas of City 100-year floodplain including ponding areas and sheet
flow areas with average depths of 1-3 feet.
There is a 1% annual chance that these areas will be flooded.
High Risk
FEMA Floodway - Area of 100-year floodplain with greatest depths and
fastest velocities.
Erosion Buffer Limits
0 240 480 720 960120
Feet
PROSPECT & I-25 ODP
FORT COLLINS STORMWATER CRITERIA MANUAL Hydrology Standards (Ch. 5)
3.0 Rational Method
3.2 Runoff Coefficients
Page 4
3.2 Runoff Coefficients
Runoff coefficients used for the Rational Method are determined based on either overall land use or
surface type across the drainage area. For Overall Drainage Plan (ODP) submittals, when surface types
may not yet be known, land use shall be used to estimate flow rates and volumes. Table 3.2-1 lists the
runoff coefficients for common types of land uses in the City.
Table 3.2-1. Zoning Classification - Runoff Coefficients
Land Use Runoff Coefficient (C)
Residential
Urban Estate 0.30
Low Density 0.55
Medium Density 0.65
High Density 0.85
Commercial
Commercial 0.85
Industrial 0.95
Undeveloped
Open Lands, Transition 0.20
Greenbelts, Agriculture 0.20
Reference: For further guidance regarding zoning classifications, refer to the Land Use
Code, Article 4.
For a Project Development Plan (PDP) or Final Plan (FP) submittals, runoff coefficients must be based on
the proposed land surface types. Since the actual runoff coefficients may be different from those
specified in Table 3.2-1, Table 3.2-2 lists coefficients for the specific types of land surfaces.
Downtown Timnath Area
See Map B-5
TIMNATH
RESERVOIR
E
E COUNTY ROAD 40
E PROSPECT RD
!(SB 1251047 ac.43%
!(SB 1263423 ac.15%
!(SB 2634 ac.66%
!(SB 2733 ac.20%
!(SB 2835 ac.20%
!(SB 3145 ac.25%
!(SB 309 ac.30%!(SB 2537 ac.15%
!(SB 3444 ac.61%
!(SB 432 ac.80%!(SB 732 ac.40%
!(SB 69 ac.90%
!(SB 337 ac.80%!(SB 15A43 ac.55%
!(SB 582 ac.55%
!(SB 237 ac.30%
!(SB 5A33 ac.15%
!(SB 1587 ac.20%
!(SB 1326 ac.38%!(SB 1643 ac.25%
!(SB 3256 ac.20%
!(SB 9143 ac.50%
!(SB 8197 ac.67%
!(SB 4A30 ac.70%
!(SB 1876 ac.51%
!(SB 1136 ac.39%
!(SB 1242 ac.44%
!(SB 10115 ac.55%
!(SB 14103 ac.33%
!(SB 1737 ac.45%
!(SB 2036 ac.40%!(SB 2154 ac.45%
!(SB 50A7 ac.50%
!(SB 506 ac.50%
!(SB 5214 ac.78%
!(SB 5121 ac.78%
!(SB 4884 ac.68%
!(SB 4932 ac.64%
!(SB 3310 ac.29%
!(SB 37117 ac.37%
!(SB 4420 ac.5%
!(SB 43A41 ac.44%!(SB 4656 ac.38%
!(SB 47A23 ac.43%
!(SB 4719 ac.34%!(SB 4566 ac.42%!(SB 7679 ac.35%!(SB 7928 ac.5%
!(SB 7872 ac.5%
!(SB 3948 ac.21%
!(SB 3582 ac.45%
!(SB 772 ac10%!(SB 77B2 ac.10%!(SB 80B1 ac.10%!(SB 80A4 ac.10%
!(SB 808 ac.15%!(SB 72A5 ac.30%
!(SB 7288 ac.32%!(SB 6730 ac.49%
!(SB 6851 ac.36%
!(SB 7117 ac.30%
!(SB 1201225 ac.65%
!(SB 8145 ac.25%
!(SB 8221 ac.30%!(SB 82A16 ac.10%!(SB 82B3 ac.10%
!(SB 81A6 ac.30%
!(SB 77C9 ac.25%!(SB 77D27 ac.30%
!(SB 80D10 ac.10%
!(SB 80C10 ac.10%
!(SB 8449 ac25%
!(SB 8449 ac.!(SB 82C8 ac.10%!(SB 82D109 ac.30%!(SB 7055 ac.50%!(SB 73159 ac.50%
!(SB 2247 ac.20%
!(SB 25A17 ac.10%
!(SB 2421 ac.15%
!(SB 2922 ac.20%
!(SB 267 ac.90%
!(SB 3866 ac.30%
!(SB 9A23 ac.25%
!(SB 21A77 ac.42%
!(SB 43107 ac.22%
!(SB 70A30ac
Timnath Drainage Master Plan 2018 Update
EXHIBIT B-1 - SWMM Subbasin Map
Developed Condition - North Map
Legend
SWMM Subbasins Developed Imperv.
0 - 6%
7 - 20%
21 - 35%
36 - 50%
51 - 65%
66 - 80%
81 - 100%
SWMM Subbasin (Name, Area - Ac, % Imp.)
SWMM Routing Link q
600
Feet
File: F:\32-1881.00 Timnath Master Plan Update\GIS\MXD\AppendixMaps\AppB_Future\B-1 - FUT_BasinMap_North.mxd - Plot By: SimpsonM - Date: 8/21/2018
TRIC SPILL B
TRIC SPILL C
TRIC SPILL D
TRIC SPILL E
TRIC
TRIC 100yr
Spill Boundary (E.C.)
Timnath
Reservoir
TRIC SPILL A 350 cfs Max Capacity
C A R R I A G E
P K W Y
E PROSPECT RD
S E F R O N TA G E RD
S E F R O N T A G E R D
4 9 1 3 .5
4 9 1 2
Timnath Reservoir Inlet Canal Spills Map
q
SRH-2D Model Results (Existing 100-year)
Document Path: F:\32-1881.00 Timnath Master Plan Update\GIS\MXD\TRIC Spills\TRIC Spills_100yr Existing.mxd Date: 8/21/2018
Legend
TRIC 100-year WSEL Contours (Existing)
TRIC 100-year Boundary (Existing)
850
Feet