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VICINITY MAP
Sage Creek
Subdivision
Ft. Collins, CO
Location shown is
approximate.
no scale
Prepared by the
SEAR -BROWN
Group
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Ft Cogru, CO BMI
PK (970) 4U-5922
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April 1999
A
APPENDIX A
VICINITY MAP
VIII. REFERENCES
Storm Drainage Design Criteria and Construction Standards by the City of Fort Collins,
Colorado, May 1984, interim revision January 1997.
2. Erosion Control Reference Manual for Construction Sites by the City of Fort Collins,
Colorado, January 1991.
3. McClellands Basin Master Drainage Plan, by Greenhorne and O'Mara, Inc., June 1986.
4. McClellands Basin 100-Year Master Plan Update (County Road 9 to Fairway Estates) for
Proposed Modifications to the Oakridge Village Regional Detention Pond, April 1996.
5. Floodplain Modeling Report, McClelland's Channel by The Sear -Brown Group, Fort Collins,
Colorado, February 14, 2000.
6. Final Drainage and Erosion Control Study, Harvest Park by The Sear -Brown Group, Fort
Collins, Colorado, October 1999.
12
The proposed erosion control concepts adequately provide for the control of wind
and rainfall erosion from the Sage Creek development. Through the construction of
the proposed erosion control concepts, the City of Fort Collins performance standard
shall be met. The proposed erosion control concepts presented in this report and
shown on the erosion control plan are in compliance with the City of Fort Collins
Erosion Control Criteria.
11
detention pond over a forty (40) hour time period, thus allowing sediments and
pollutants to settle out and not be transported directly into the McClellands Basin
Drainageway,
All construction activities must also comply with the State of Colorado permitting
process for Stormwater Discharges Associated with Construction Activity. A
Colorado Department of Health NPDES permit must be obtained by the owner before
construction grading can begin within this development.
VII. CONCLUSIONS
A. Compliance with Standards
All computations that have been completed within this report are in compliance with
the City of Fort Collins Erosion Control Reference Manual for Construction Sites
and the Storm Drainage Design Criteria Manual. In addition, all computations are
in compliance with the McClellands Basin Master Plan.
B. Drainage Concept
The proposed drainage concepts presented in this report and on the construction plans
adequately provide for the transmission of developed on -site runoff to the existing
and proposed drainage facilities at the northern and eastern property lines of the
subject site. The combination of onsite street capacities in the curb and gutter and
the onsite storm drain system will provide for the 2-year and the 100-year developed
flows to reach the future detention ponds at the northern perimeter of this site. The
detention ponds will outlet into the McClellands Basin Drainageway and the flows
shall be carried east and south downstream to the Fossil Creek Reservoir Inlet Ditch
as historically occurs.
If, at the time of construction for some unforeseen reason, groundwater is
encountered, a Colorado Department of Health Construction De -watering Permit is
required.
C. Stormwater Quality Concept
The proposed design has addressed the water quality aspect of stormwater runoff
through the use of various Best Managemeni Practices (BMPs) for the treatment of
storm water. Volumes in Ponds A and B have been extended to accommodate Water
Quality Capture Volume (WQCV, see calculation in the Appendix).
D. Erosion Control Concept
10
This development lies within the Moderate Rainfall Erodibility Zone and the
Moderate Wind Erodibility Zone per the City of Fort Collins zone maps. The
potential exists for moderate erosion problems after completion of the Sage Creek
improvements, due to some existing and proposed site slopes of greater than 2
percent. It is also anticipated that the project site improvements will be subject to
both wind and rainfall erosion before new vegetation can take hold or before the new
residential lots are developed.
The Erosion Control Performance Standard (PS) during and after construction for
this project was computed to be 80.7 and 95.0, respectively, per the criteria in the
City of Fort Collins Erosion Control Reference Manual for Construction Sites. The
Effectiveness (EFF) of the proposed erosion control plan was calculated to be 81.8
during construction and 96.3 after construction. Therefore, the erosion control plan
below meets the City of Fort Collins' requirements. A copy of the calculation has
been included in the Appendix. An erosion control escrow cost estimate of $66,300
is also included in the Erosion Control section of the Appendix.
B. Specific Details
Before grading or trenching begins within the project site, a sediment fence shall be
installed at the northern and eastern perimeters (downstream perimeters) of the
construction site. After overlot grading is completed, all disturbed areas not in a
roadway area shall have temporary vegetation seed applied. After seeding, a hay or
straw mulch shall be applied over the seed at a rate of 2 tons/acre minimum, and the
mulch shall be adequately anchored, tacked, or crimped into the soil.
After overlot grading and utility installations have been completed, the
parking/driveway surfaces shall receive curb, gutter, and pavement surfaces. The
pavement structure shall be applied as soon as possible after the utilities are installed.
After installation of the storm drains, riprap protection shall be installed at the
outlets.
If the disturbed areas will not be built on within one growing season, a permanent
seed shall be applied. After seeding, a hay or straw mulch shall be applied over the
seed at a minimum rate of 2 tons/acre, and the mulch shall be adequately anchored,
tacked or crimped into the soil. In the event a portion of the roadway pavement
surface and utilities will not be constructed for an extended period of time after
overlot grading, a temporary vegetation seed and mulch shall also be applied to the
roadway areas as discussed above.
The grass lined detention ponds will be completed after other site infrastructure has
been constructed. When the detention ponds are finished, they will include multi -
staged outlet works and will be equipped with water quality riser pipes. The wate;
quality riser pipes will allow the first flush of stormwater runoff to filter out of each
9
A HEC-RAS analysis was done of the existing condition McClellands Basin
Drainageway. This analysis begins approximately 200 feet downstream of County
Road 9 and concludes 100 feet upstream of the western property line. The existing
corrugated metal pipe arch culvert under County Road 9 is 64 inches x 43 inches and
is 43 feet in length. Based on the current Master Plan SWMM analysis the flow in
the McClellands Basin Drainageway upstream of County Road 9 is 1002 cfs. The
downstream flow of County Road 9 is 1,422 cfs based on the current Master Plan
SWMM. Based on these flows the depth of flow over County Road 9 with the
existing culvert is 1.16 feet. The elevation of the existing County Road 9 at the
culvert crossing is 4905.
A second HEC-RAS analysis was done which included the proposed box culverts
under County Road 9 and upstream at Corbett Drive. The same flow rates were used
as in the existing condition HEC-2 analysis as stated previously. The proposed box
culvert under County Road 9 shall be 6 feet high and 25 feet wide. The proposed box
culvert under Corbett Drive will be three sided, with the creek as the bottom portion,
left in its natural condition. This will remain the case until a 100-year event occurs.
During a 100-year storm it is likely that the concrete sides of the box will be fully
exposed. Based on this, the box culvert was modeled in its fully exposed size of 7
feet x 20 feet. With the proposed box culvert in County Road 9 the 100-year water
surface elevation at County Road 9 is 4905.52. The low point in the proposed
County Road 9 is approximately 4907.00. With the proposed box culvert under
Corbett Drive the 100-year water surface elevation is 4911.53. The low point in the
proposed Corbett Drive is approximately 4913.70.
STORMWATER QUALITY
A. General Concept
The water quality of stormwater runoff must be addressed on all final design utility
plans. The Sage Creek development is anticipating construction beginning in Spring
2000. Ponds A and B have been upsized to accommodate the Water Quality Capture
Volume as required by the City of Ft. Collins (see calculations in the Appendix).
The project will address all stormwater runoff quality concerns through the use of
various Best Management Practices for the treatment of stormwater runoff. Best
Management Practices (BMPs) for the treatment of storm water runoff include
installation of silt fence, rough irregular surfaced soils during grading operations,
WQCV, and straw or hay dry mulch of disturbed soils. .
VI. EROSION CONTROL
A. General Concept
8
site is 28.87 cfs for the 100-year storm and 11.59 cfs for the 10-year storm.
Detention Pond B outlet works is designed to release 9.59 cfs during the 10-year
event and 17.91 cfs during the 100-year event.
Sub -Basin OS4:
Sub -Basin OS4 shall maintain historic flows to McClellands Basin Drainage way.
The 100-year flows from this basin are approximately 2.45 cfs which are not
historically nor developed channelized flows and therefore are considered incidental
flows to the McClellands Basin Drainage way.
A SWMM analysis of the proposed Sage Creek development has been done. When
the model is finalized and approved it can be inserted into the Master Plan update
currently being prepared by the City's consultant. The results of the SWMM analysis
are included in Appendix C. The site was broken into 5 basins as shown on the
SWMM schematic.
SWMM Basin 100:
SWMM Basin 100 is composed of rational basins Al, OS2, OS3 and OS4. The total
area of SWMM Basin 100 is 6.52 acres and drains historic undeveloped flow directly
into McClellands Basin Drainage way via Swale Al. SWMM sub -basin 100 is
composed of McClellands Basin.
SWMM Basin 110:
SWMM Basin 110 is composed of rational basins A2-A8, Al 1-Al2 and PA. The
total area of SWMM basin 110 is 16.36 acres and drains into detention Pond A.
SWMM Basin 120:
SWMM Basin 120 is composed of rational basins A9, A10, A13 and A14. The total
area of SWMM basin 120 is 10.11 acres and drains into detention Pond A.
SWMM Basin 130•
SWMM sub -basin 130 is composed of rational basins B1-B6, B8-B10 and PB. The
total area of SWMM basin 130 is 24.64 acres and drains into detention Pond B.
SWMM Basin 140:
SWMM sub -basin 140 is composed of rational basin B7. The total area of SWMM
basin 140 is 0.10 acres and is released undetained to McClellands Ditch.
The basin widths for the site were determined by taking the average length of travel
from the limit of the SWMM basin to the flow concentratio,i point and dividing that
into the area of the basin. The percent impervious values and slopes were determined
from the site plan.
7
Inlet ST-B8:
Inlet ST-B8 intercepts 100-year design flows of approximately 19.75 cfs from
drainage sub -basin B8.
Storm Drain B8•
Storm Drain B8 picks up 100-year design flows of 19.75 cfs at Inlet ST-B8. These
flows are transported through approximately 288.19 L.F. of 21" RCP into Pond B at
ST-FES-118. Storm Drain B8 accepts flows from sub -basin B8.
Swale B8:
Swale B8 is located over Storm Drain B8. Swale B8 is designed to carry 100-year
design flows of 19.75 cfs in case Inlet B8 becomes plugged. Swale B8 empties into
Sage Creek Road and drains sub -basin B8 in an emergency without inundating any
homes.
Inlet ST-B9A:
Inlet ST-139A intercepts 100-year design flows of approximately 48.09 cfs from
drainage basins B9 and B 10.
Inlet ST-B9B:
Inlet ST-B9B intercepts 100-year design flows of approximately 7.69 cfs from
drainage basin B6.
Storm Drain B9•
Storm Drain B9 picks up 100-year design flows of 48.09 cfs at Inlet ST-119A. These
flows are transported through approximately 30.00 L.F. of 27 RCP to Inlet ST-119B
where Storm Drain B9 picks up an additional 100-year design flow of 7.69 cfs. The
combined flows of 55.78 cfs are transported through approximately 46.00 L.F. of 27"
RCP into Pond B at ST-FES-119. Storm Drain B9 accepts flows from sub -basins B6,
B9 and B10.
Pond B Eaualization Pipe:
The Pond B Equalization Pipe is designed to carry 100-year design flows of
approximately 70 cfs from west to east or east to west. This will allow uninterrupted
flows during 100-year peak periods so the separated ponds will act as one.
Detention Pond B:
Pond B accepts direct flows from sub -basin PB of 25.87 cfs during the 100-year
storm event. Detention Pond B will release to McClellands Basin Drainageway via
a staged outlet control structure and approximately 82 L.F. of 27" RCP. The
outlet works will be designed and constructed to limit the discharge into the
McClellands Basin Drainageway to 0.2 cfs/acre for the 10-year storm and 0.5
cfs/acre for the 100-year storm (in accordance with the Master Plan for
McClellands Basin). Based on these criteria, the total allowable release rate for the
6
L.F. of 30" RCP into Pond A at ST-FES-A10. Storm Drain A10 accepts flows from
sub -basins A6, A9, A10, A13 and A14.
Detention Pond A:
Detention Pond A accepts direct flows from sub -basin PA of 21.89 cfs during the
100-year storm event. Detention Pond A will release to McClellands Basin
Drainageway via a staged outlet control structure and approximately 85 L.F. of
18" RCP. The outlet works will be designed and constructed to limit the discharge
into the McClellands Basin Drainageway to a maximum of 0.2 cfs/acre for the 10-
year storm and 0.5 cfs/acre for the 100-year storm (in accordance with the Master
Plan for McClellands Basin). Based on these criteria, the total allowable release
rate for the site is 28.87 cfs for the 100-year storm and 11.59 cfs for the 10-year
storm. Detention Pond A outlet works is designed to release 2.00 cfs during the
10-year event and 8.80 cfs during the 100-year event.
Sub -Basin Al:
Sub -Basin Al is composed of 0.23 acres of developed backyard 100-year flows of
1.28 cfs. These flows have a time of concentration of 7 minutes and are release
undetained to Swale Al as historically occurs.
`B' BASINS:
Inlet ST-B3A:
Inlet ST-B3A intercepts 100-year design flows of approximately 18.58 cfs from
drainage basins B1, B2 and B3.
Inlet ST-B3B:
Inlet ST-B3B intercepts 100-year design flows of approximately 1.00 cfs from
drainage basin B7.
Z� So
Storm Drain B3•
Storm Drain B3 picks up 100-year design flows f 18.58 cfs at Inlet ST-B3A. These
flows are transported through approximately L.F. of 18" RCP to Inlet ST-11311
where Storm Drain B3 picks up an additional 100-year design flow of 1.00 cfs. The
combined flows of 19.58 cfs are transported through approximately 4W L.F. of 27"
RCP into Pond A at ST-FES-B3. Storm Drain B3 accepts flows froi sub -basins B 1,
B2, B3 and B7. `'12.00
Swale B4:
Swale B4 is located on the east side of Corbett Drive near McClellands channel.
Swale B4 is designed to carry 100-year design flows of 6.68 cfs from Corbett Drive
and direct flows from sub -basin B5 to Pond B. Swale B4 intercepts flows from sub -
basins B4 and B5.
5
`A' BASINS:
Swale Al:
Swale Al located on the northwest comer of the site intercepts 100-year design flows
of approximately 4.57 cfs from offsite sub -basin OS L These flows are allowed to
flow into McClellands Drainageway un-detained as historic offsite flows.
Swale A5:
Swale A5 located at the northeast end of the Rabbit Creek Road cul-de-sac intercepts
100-year design flows of approximately 26.43 cfs from sub -basins A3, A4, A7 and
Al 1. These flows are then picked up at the upstream end of Storm Drain A5.
Inlet ST-A5A:
Inlet ST-A5A intercepts 100-year design flows of approximately 26.47 cfs from
drainage basins A5, A8 and Al2.
Inlet ST-A5B:
Inlet ST-A5B intercepts 100-year design flows of approximately 1.69 cfs from
drainage basin A2.
Storm Drain A5:
Flared End Section (FES) ST-FES-A5A picks up flows of 26.43 cfs from Swale A5.
These flows are transported through approximately 295.50 L.F. of 24" reinforced
concrete pipe (RCP) to Inlet ST-A5A where Storm Drain A5 picks up an additional
26.47 cfs. The combined flows of 52.90 cfs are transported through approximately
38 L.F. of 27" RCP to Inlet ST-A5B where an additional 1.69 cfs is accepted into
Storm Drain A5. The combined flow of 54.59 is transported through approximately
58.90 L.F. of 27" RCP into Pond A at ST-FES-A511. Storm Drain A5 accepts flows
from sub -basins A2, A3, A4, A5, A7, A8, All and Al2.
Inlet ST-AlOA:
Inlet ST-AIOA intercepts 100-year design flows of approximately 39.68 cfs from
drainage basins A9, A10, A13 and A14.
Inlet ST-AlOB:
Inlet ST-AIOB intercepts 100-year design flows of approximately 3.88 cfs from
drainage basin A6.
Storm Drain A10:
Storm Drain A10 picks up 100-year design flows of 39.68 cfs at Inlet ST-AlOA.
These flows are transported through approximately 34 L.F. of 27" RCP to Inlet ST-
AlOB where Storm Drain A10 picks up an additional 100-year design flows of 3.88
cfs. The combined flows of 43.56 cfs are transported through approximately 101
4
D. Hydraulic Criteria
All hydraulic calculations within this report have been prepared in accordance with
the City of Fort Collins Drainage Criteria and are also included in the Appendix.
E. Variances from Criteria
No variances are being sought for the proposed project site.
IV. DRAINAGE FACILITY DESIGN
A. General Concept
Over 99% of the total on -site runoff produced by the developed portions (not
including the buffer zone) of the proposed Sage Creek development will be routed
to one of the two proposed detention ponds via curb and gutter, cross -pans, sidewalk
chases, inlets, and underground storm drains. The outflow from the detention ponds
will be released into the McClellands Basin Drainageway and will then be conveyed
under County Road 9 through a pair of box culverts (to be designed and constructed
by the Harvest Park development). The McClellands Basin Drainageway enters the
Fossil Creek Reservoir Inlet Ditch. approximately 1.2 miles southwest of the site.
A SWMM analysis was done of the site in order to determine the volume
requirements of the proposed detention ponds on the site. A HEC-RAS analysis has
been done of the McClellands Basin Drainageway in order to determine the existing
and proposed flood plain limits adjacent to the site. The existing condition has been
prepared in conjunction with the Harvest Park development immediately to the north
of the Sage Creek site, and a copy of the most recent revision is included in this
report. The developed condition HEC-2 model has been revised and updated to
HEC-RAS, also in conjunction with the Harvest Park development, a copy of the
most recent revision has been included in this report. All relevant calculations
included in this report are based on the updated HEC-RAS model.
B. Specific Details
The proposed Sage Creek development contains a total area of approximately 54.33
acres, which has been divided into twenty-nine (29) sub -basins for Rational Method
runoff analysis. Basin designations with an `A' prefix drain to Pond A, basin
designations with a `B' prefix drain to Pond B. All basins drain to the north and/or
east, and are routed through on -site detention facilities, and eventually into the
McClellands Basin Drainageway. Please refer to Appendix B and the Drainage and
Erosion Control Plan in the back of this report.
3
east along the northern edge of the project boundary. The McClellands Basin
Drainageway eventually drains into the Fossil Creek Reservoir Inlet Ditch, which
transmits water to the Fossil Creek Reservoir.
B. Sub -basin Description
The area encompassed by the proposed Sage Creek development has been divided
into 26 sub -basins for Rational Method calculations. Runoff is routed to one of two
detention ponds (Ponds A and B). Ponds A and B will be located 50 feet south of the
existing McClellands Basin Drainageway. Pond B is broken out into two ponds with
a culvert connecting the two, this culvert allows uninterrupted flows in the 100-year
event between the ponds. These on -site basins are proposed to be developed with
residential housing and street improvements, including improvements to County
Road 9 and County Road 36. These sub -basins are shown on the Drainage and
Erosion Control Plan in the back pocket of this report.
This development will also include improvements to the portions of County Road 9
and County Road 36 that are adjacent to the site. A majority of the runoff from the
roads will be directed onto the site and detained in the proposed detention ponds, in
accordance with City of Fort Collins directives.
IIl. DRAINAGE DESIGN CRITERIA
A. Regulations
The City of Fort Collins Storm Drainage Design Criteria is being used for the subject
site.
B. Development Criteria Reference and Constraints
The criteria and constraints from the McClellands Basin 100-year Master Plan and
subsequent update dated April 1, 1996 are being utilized in this Final Drainage
Study. With this development, on site detention will be provided and flows will be
released into the McClellands Basin Drainageway at the rates defined by the Master
Plan.
C. Hydrologic Criteria
The Rational Method for determining surface runoff was used for the project site.
The recently adopted 2-year and 100-year storm event intensities provided by the
City of Fort Collins were used in calculating runoff values. Site hydrologic modeling
was completed using SWMM for the purposes of pond sizing. These calculations
and criteria are included in the Appendix of this report. .
N
FINAL DRAINAGE AND
EROSION CONTROL STUDY
FOR SAGE CREEK
FORT COLLINS, COLORADO
GENERAL LOCATION AND DESCRIPTION
A. Location
Sage Creek is bounded by County Road 9 on the east, private residences with large
lots on the west, the McClellands Basin Drainageway and the Harvest Creek
Subdivision on the north, and by County Road 36 on the south.
The site location can also be described as situated in the south half of the southeast
1/4 of Section 5, Township 7 North, Range 68 West of the 6th Principal Meridian,
City of Fort Collins, Larimer County, Colorado. A map showing the site location is
included in the Appendix.
B. Description of Property
The proposed Sage Creek development is being proposed as a residential
development within the City of Fort Collins Zoning. The property consists of
approximately 54.33 acres of land, of which a majority is currently cultivated
farmland. This includes the 50-ft. (3.4 acre) no -impact buffer zone between the
McClelland's drainage -way and the developed lots and associated facilities.
There is one existing concrete lined irrigation channel located in the western half of
the site. The channel will be removed with the Sage Creek development. This
channel has been used historically for irrigation of the existing adjacent farmland
only and has not been a drainage conveyance for storm events. The removal of this
channel will not affect any of the surrounding farm irrigation channels.
The topography generally slopes north-northeast towards the existing McClellands
Basin Drainageway at approximately 0.6 — 4.5 percent. The McClellands Basin
Drainageway runs from west to east along the northern edge of the project boundary.
DRAINAGE BASINS
A. Major Basin Description
The Sage Creek development lies within McClellands Basin. The McClellands
Basin Drainageway flows in a generally southeast direction, and runs from west to
APPENDIXA: VICINITY MAP......................................................................................................................................................................... A
APPENDIX B: RATIONAL METHOD HYDROLOGY AND STREET CAPACITIES............................................................................... B
APPENDIX C: SWMM ANALYSIS AND POND STORAGE REQUIREMENT.......................................................................................... C
APPENDIXD: HEC-2 ANALYSIS..................................................................................................................................................................... D
APPENDIX E: STORM DRAINS AND INLETS............................................................................................................................................... E
APPENDIX F: RIPRAP DESIGN ................................... ..........
............................................................................................................................ F
APPENDIX G: POND VOLUMES AND POND OUTLET STRUCTURE DESIGN.....................................................................................G
APPENDIX H: EROSION CONTROL AND WATER QUALITY.................................................................................................................. H
APPENDIX I: TABLES AND FIGURES.............................................................................................................................................................I
APPENDIX J: HEC-2 FLOOD PLAIN MAP, SWMM BASIN MAP
BACK POCKET 1
APPENDIX K: DRAINAGE AND EROSION CONTROL PLAN DRAWING SHEET ................................................... BACK POCKET 2
TABLE OF CONTENTS
DESCRIPTION
PAGE
I.
GENERAL LOCATION AND DESCRIPTION................................................................................................................I
A.
LOCATION.........................................................................................................................................................................
I
B.
DESCRIPTION OF PROPERTY.............................................................................................................................................
I
II.
DRAINAGE BASINS...........................................................................................................................................................I
A.
MAJOR BASIN DESCRIPTION.............................................................................................................................................
I
B.
SUB -BASIN DESCRIPTION...................................................................................................................................................2
III.
DRAINAGE DESIGN CRITERIA................................................................................................................................2
A.
REGULATIONS...................................................................................................................................................................
2
B.
DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS..............................................................................................2
C.
HYDROLOGIC CRITERIA...................................................................................................................................................2
D.
HYDRAULIC CRITERIA......................................................................................................................................................3
E.
VARIANCES FROM CRITERIA.............................................................................................................................................3
IV.
DRAINAGE FACILITY DESIGN.......................................................................................................................................3
A.
GENERAL CONCEPT..........................................................................................................................................................3
B.
SPECIFIC DETAILS.............................................................................................................................................................3
V.
STORMWATER QUALITY...............................................................................................................................................6
A.
GENERAL CONCEPT..........................................................................................................................................................6
VI.
EROSION CONTROL.........................................................................................................................................................8
A.
GENERAL CONCEPT..........................................................................................................................................................
8
B.
SPECIFIC DETAILS.............................................................................................................................................................
I
VII.
CONCLUSIONS............................................................................................................................................................10
A.
COMPLIANCE WITH STANDARDS.....................................................................................................................................
10
B.
DRAINAGE CONCEPT.......................................................................................................................................................
10
C.
STORMWATER QUALITY CONCEPT.................................................................................................................................
10
D.
EROSION CONTROL CONCEPT........................................................................................................................................
10
VIII.
REFERENCES..............................................................................................................................................................12
THE SEAR -BROWN GROUP
FULL -SERVICE DESIGN PROFESSIONALS
209 SOUTH MELDRUM
FORT COLLINS, COLORADO 80521-2603
970-482-5922 FAX:970-482-6368
March 10, 2000
Mr. Basil Hamdan
City of Fort Collins
Water Utilities--Stormwater
700 Wood Street
Fort Collins, Colorado 80522
RE: Final Development Plan Drainage and Erosion Control Study for Sage Creek
Dear Basil:
We are pleased to submit to you, for your review and approval, this Final Development Plan
Drainage and Erosion Control Study for Sage Creek. All computations within this report have been
completed in compliance with the City of Fort Collins Storm Drainage Design Criteria.
We appreciate your time and consideration in reviewing this submittal. Please call if you have any
questions.
Respectfully,
The Sear -Brown Group
Prepared by:
Lee Cunning, P.E.
Design Engineer
cc: File 434-021A
Jim Postle, The James Company
Reviewed by:
Les Crawford, P.E.
Project Manager
NEW YORK • PENNSYLVANIA
COLORADO•UTAH•WYOMING
STANDARDS IN EXCELLENCE
EQUAL OPPORTUNITY EMPLOYER
I
I
Final Development Plan
Drainage and Erosion
i Control Study
Sage Creek
Fort Collins, Colorado
March 10, 2000
I
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17
L-1
I
THE
SEAR -BROWN
GROUP
Standards in Excellence
I