HomeMy WebLinkAboutDAKOTA RIDGE PUD THIRD FILING PRELIMINARY - 60 91K - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPRELIMINARY
DRAINAGE .REPORT
FOR,
DAKOTA. RIDGE P.U.D. TST. INQ
THIRD FILING
SUBNAOTTED TO
THE CITY OF
FORT COLLINS
MAY. ' EEEiiB
0
Mr. Glen Schleuter
City of Fort Collins
Stormwater Utility
P.O. Box 580
Fort Collins, CO 80522
RE: Dakota Ridge P.U.D. Third Filing
Preliminary Drainage Report
Project No. 10-746-050
Dear Glen:
May 2, 1994
The attached report presents the Preliminary Drainage information for the Dakota Ridge Planned
Unit Development (P.U.D.) Third Filing. The information is submitted in accordance with the
requirements of the City of Fort Collins Storm Drainage Design Criteria and Construction
Standards, most particularly Section 2.1 "Preliminary Submittal Requirements - Drainage and
Erosion Control". The 24" x 36" Drainage Exhibit attached to this report was also produced
following the guidelines of the Section 2.1 requirements.
The Dakota Ridge P.U.D. is located within the extreme downstream end of the Foothills Basin,
and also falls within an area formerly masterplanned under the Pinecone Overall Development
Plan (O.D.P.). The O.D.P., which defines the runoff control requirements for the Dakota Ridge
project, is currently in the process of being updated. The preliminary results of the update
indicate that stormwater detention is not required, and therefore this Preliminary Drainage
Report discusses only stormwater control and conveyance facilities for the project area.
Thank you for your consideration and review of this project. We would be happy to supply
_additional_ information or clarification, if necessary.
Sincerely,
TST INC., CONSULTING ENGINEERS
I S zann C. Bassinger
TSTINC.748 Whalers Way - BuildingD 102 lnvemess Terrace East
! Fort Collins, CO 80525 Suite 105
Consulting Engineers (303) 226-0557 Englewood, CO 80112
Metro Denver (303) 595-9103 (303) 792-0557
Fax (303) 226-0204 Fax (303) 792-9489
DAKOTA RIDGE P. U. D. THIRD FILING
PRELIMINARY DRAINAGE REPORT
TABLE OF CONTENTS
Page
1.0 INTRODUCTION
1.1 Project Location & Description ............................ 1
1.2 Master Drainage Basin .................................. 1
2.0 HISTORIC CONDITIONS . . .............. :.....: 3
3.0 DEVELOPED CONDITIONS PLAN
3.1 Project Requirements ....................... ........... 4
3.2 General Stormwater Management Plan ........................ 4
3.3 Criteria for Final Design ................................ 4
FIGURES
Figure 1 - Vicinity Map ........................................ 2 .
TECHNICAL APPENDIX
Preliminary Recommendations for Pinecone O.D.P.
SHEETS
Preliminary -Drainage Exhibit (in Map Pocket) Sheet 1 of 1
TST, INC. 10-746-050 ii May 2, 1994
1 1.0 INTRODUCTION
1.1 Project Location & Description
The Dakota Ridge P.U.D. Third Filing consists of approximately 21 acres of proposed single
family residential use, located in Section 29, Township 68 North, Range 7 West, of the 6th
P.M. in the City of Fort Collins. As indicated by the Vicinity Map on the next page, the project
area is located east of Timberline Road and north of Horsetooth Road. A City owned open
space and park area of approximately 7.7 acres is located adjacent to the project's southwest
corner. The design and consideration of storm drainage control facilities for the open space/park
area is included herein at the City's. request.
1.2 Master Drainage Basin
The project area falls within the Foothills Basin Master Drainage Plan, and it is directly adjacent
and tributary to the south side of the Foothills Basin Regional Channel (currently under design).
The Dakota Ridge P.U.D. Third Filing is also included with the Pinecone Overall Development
Plan, which established the overall runoff control requirements and facility configuration for the
entire area.
It TST, INC. 10-746-050 1 May 2, 1994
N.T.S
TST INC.
10-746-050
DAKOTA RIDGE P.U.D THIRD FILING
VICINITY MAP
5/2/94
2.0 HISTORIC CONDITIONS
This area was previously in agricultural use as a portion of the Colorado State University
Agricultural Research Facility. As an agricultural research facility, the area contained many
farm/service roads and small irrigation or irrigation return flow ditches. The topography is
generally flat. Historical runoff patterns have been generally to the north and east into the
existing drainage channel (currently under redesign as the improved Foothills Basin Regional
Channel) and thereafter to the Fossil Creek Reservoir Inlet Ditch (FCRID).
With the sale of the property for development purposes the service roads and small irrigation
ditches are no longer of use, and can be removed.
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_ TST, INC. 10-746-050 3
May 2, 1994
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3.0 DEVELOPED CONDITIONS PLAN
3.1 Project Requirements
The Dakota Ridge P.U.D. Third Filing area is contained within the area addressed within the
Pinecone Overall Development Plan (O.D.P.). The O.D.P. is currently in the process of being
updated and the preliminary results of the update indicate that stormwater detention is not
required. Information to support this recommendation has been obtained from Lidstone &
_ Anderson, the firm producing the O.D.P. Update, and is included within the Technical
Appendix. The remainder of this report, and the discussion of stormwater control and
conveyance facilities for the project area, is based on the conclusions presented in that
information, and therefore no stormwater detention has been provided at the site.
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3.2 General Stormwater Management. Plan
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The Preliminary Drainage Exhibit prepared for this report (see Map Pocket) indicates the
proposed site layout for the Dakota Ridge P.U.D. Third Filing, and also for the adjacent City
of Fort Collins park and open space area. The stormwater conveyance system will consist of
directing onsite overland flow to street surfaces, curb and gutter flow, grated curb inlets, and
then storm sewer pipe daylighting to the improved Foothills Regional Channel. There are no
significant off -site flow, contributions to the project area.
The park/open space area drainage will continue to flow overland to the northeast, where it will
be directed in an open channel to the north, crossing beneath Pinecone Circle in a culvert, and
then continuing north, through a drainage/utility easement, in an open channel to the Foothills
Regional Channel.
3.3 Criteria for Hnal Design
1— The -final -design of .the-stormwater control and conveyance facilities shall conform with the
current City of Fort Collins Storm Drainage Design Criteria & Construction Standards (1v1ay
1984, with March 1991 updates). The project area is small, and therefore the Rational Method
will be used to determine runoff flows for the initial (2 year) and major (100 year) storms. The
runoff flows for the 10 year storm will be determined for the park/open space area in order to
provide adequate capacity in the design of the proposed culvert under Pinecone Circle, which
is a collector roadway.
The Preliminary Drainage Exhibit indicates the proposed finished street grades and flow
directions, preliminary catch basin locations and flowline elevations, crosspan locations, storm
sewer and culvert locations, and storm sewer outfalls adjacent to the Foothills Regional Channel.
Delineation and sizing of sub -basins for the Rational Method calculations is also indicated.
TST, INC. 10-746-050 4 May 2, 1994
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The requirements of the following sections of the Design Criteria will be adhered to during the
final design of the stormwater conveyance system:
Section 4.Streets: Pavement encroachment limits, inlet sizing and location, crosspans.
Section 5 Storm Sewers: Sizing, pipe materials, utility crossing, inlet capacity, manhole
size and spacing.
1 Section6. Culverts: Capacity and design.
T The final design will also include the provisions for the implementation of sediment and erosion
control measures on the construction site.
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TST, INC. 10-746-050
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May. 2, 1994