HomeMy WebLinkAboutPLATT PROPERTY PUD PRELIMINARY - 3 90B - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPRELIMINARY DRAINAGE & EROSION
CONTROL REPORT
FOR
PLATT PROPERTIES
SINGLE FAMILY DEVELOPMENT
AT
NORTHEAST CORNER OF REGENCY DRIVE
AT WAKEROBIN LANE
MAY 6, 1991
PREPARED FOR:
THE GROUP
401 WEST MULBERRY
FORT COLLINS, COLORADO 80521
PREPARED BY: PARSONS & ASSOCIATES CONSULTING ENGINEERS
432 LINK LANE PLAZA
FORT COLLINS, COLORADO 80524
303=221-2400
4
PRELIMINARY DRAINAGE & EROSION CONTROL REPORT
FOR
PLATT PROPERTIES SINGLE FAMILY DEVELOPMENT
AT
NORTHEAST CORNER OF REGENCY DRIVE AND WAKEROBIN LANE
INTRODUCTION
This preliminary drainage and erosion control investigation
has been performed for the purpose of providing planning and
preliminary design information for the development of approximately
31.86 acres at the northeast corner of Regency Drive and Wakerobin
Lane. The City of "Fort Collins Storm Drainage Design Criteria and
Construction Standards" was used as the basis for guidelines and
criteria throughout this investigation.
SITE INVESTIGATION
The study area is situated in the southeast one -quarter of
Section 34, Township 7 North, Range 69 West of the 6th Principal
Meridian, City of Fort Collins, Larimer County, Colorado. The site
is bounded by Wakerobin Lane on the south, Seneca Drive on the
west, the proposed Troutman Parkway on the north and the Pleasant
Valley and Lake Canal on the east. This site is presently
undeveloped and consists of primarily native grasses as a ground
cover. Site slopes generally average about 1%.
The proposed usage of the site is as follows:
PROPOSED USES
Description Acres
R/W 1.3 4.1 %
Open Space Detention 6.0 18.8 %
Lots 24.6 77.1 %
TOTAL 31.9 100 96
It is anticipated that the project will develop between 98 and
100 lots in two phases. These phases correspond closely to the
drainage basin boundary lines. Phase I will include 60 lots to the
south and Phase II will include 35-40 lots to the north.
Construction of Troutman Parkway and the temporary detention pond
will be completed in May in Phase II.
HISTORIC DRAINAGE
This site is located along the basin boundary for the
McClelland and Mail Creek Basin. This basin boundary splits the
site almost in half with approximately 21 acres flowing to the
north and approximately 19 acres flowing to the south.
Historically, all flows eventually found their way into the
Pleasant Valley and Lake Canal.
MASTER DRAINAGE
MCCLELLAND BASIN
The northerly one-half of the site flows into the
McClelland Basin. A detention basin is proposed to the
north in conjunction with construction of a future park.
MAIL CREEK BASIN
The southerly one-half of the site flows into the Mail
Creek Basin. A regional detention facility designed as
part of the Mail Creek Basin Master Plan is adjacent to
this site along Wakerobin Lane. This detention pond was
designed to handle developed flows from this property.
DEVELOPED DRAINAGE
NORTHERLY BASIN
The northerly basin consists of approximately 21 acres.
It is anticipated that these flows will be released into
a temporary detention facility with about 1.26 acre feet
of capacity.. Historic discharge will be conveyed by a
pipe under the proposed Troutman Parkway to the north.
It is anticipated that this pond will be eliminated when
a regional detention facility is constructed to the
north. Two-year flows equal 5.3 cfs and 100-year flows
equal 21.0 cfs for undeveloped conditions.
SOUTHERLY BASIN
The southerly basin consists of approximately 19 acres.
Flows from this area will be routed under Wakerobin and
into the regional detention pond. Two year flows equal
9.4 cfs and 100-year flows equal 34.8 cfs for undeveloped
conditions.
C. SEASON AND TIMING OF CONSTRUCTION
The project is divided into two phases, with the time of
construction of the first phase to begin in early
September of 1991. The overlot grading will be the first
item of construction and is expected to take
approximately 3 weeks. In terms of erosion control, this
is ideal timing since it is during the low wind season.
Additionally, there is still enough precipitation
expected after the grading is complete to allow
germination of grasses prior to the winter wind season.
Although the timing of the second phase has not been
determined, we will attempt to start construction about
the same time of the year.
Prepared under the direct supervision of:
4�l
Donald M. Parso s, P.E.
Colorado Licen e # 13131
M. P,
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