HomeMy WebLinkAboutFRONT RANGE COMMUNITY COLLEGE SOUTH PARKING LOT EXPANSION - SPAR - SPA130004 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTBOULDER I FORT COLLINS I WINTER PARK
JVA, Incorporated
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Suite 200
Fort Collins, CO 80524
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Fax: 970.225.6923
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Web site:
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October 15, 2013
Mr. Glen Schlueter
Fort Collins Utilities – Stormwater
700 Wood Street
Fort Collins, CO 80522
RE: FRCC Larimer Campus – South Parking Lot
Drainage Intent Letter for SPAR
JVA Job No. 1990.3c
Dear Glen:
JVA is currently in process of working with Oz Architecture and Front Range Community
College (FRCC) on the design of a parking lot located within the vacant lot at the northeast
corner of Clarendon Hills Drive and South Shields Street. The parking lot is proposed to be
constructed in two phases, both being located south of the existing private irrigation lateral
crossing the property. The first phase will approximately consist of 254 parking spaces and the
second phase approximately consisting of 157 parking spaces. FRCC’s intent is to construct the
first phase of parking in the near future, possibly spring of 2014. The second phase of parking is
not currently budgeted and does not have an anticipated schedule, to our knowledge, at this time.
For the consideration of future planning, FRCC is submitting both phases of parking
improvements with this SPAR submittal.
Interwest previously completed an addendum to FRCC’s Master Drainage Study that addressed
improvements within this same site, and to our knowledge, has been submitted to the City for
review. The direction of the improvements within this lot has changed, and FRCC is no longer
anticipating placement of a building within this lot. The increase of impervious area as proposed
with the parking improvements is very similar to that within Interwest’s addendum. The intent
of this parking lot project is to provide detention such that the runoff associated proposed
parking lot improvements will be detained, treated for water quality, and released at the 2-yr
historic release rate. This would be achieved by creating a detention pond, proposed to be
located on the existing FRCC campus, south of the existing parking lot. The detained runoff
would be released to the existing swale that runs along the existing parking lot, to the regional
(campus regional) detention facility. We anticipate achieving the necessary volume within this
proposed pond without any modifications to the existing regional pond. The existing site
currently drains from the southwest to the northeast and the proposed improvements will not
alter the historic drainage path. Interwest estimated that the improvements south of the existing
irrigation ditch would require approximately 0.09 acre-feet of water quality storage and 0.66
acre-feet of detention volume, with a 100-yr release rate of 1.8 cfs. All computations will be
confirmed with the final design.
The design team and FRCC’s intend to implement Low Impact Development techniques where
reasonably achievable. Conceptually we are proposing utilizing permeable pavers within the
parking lot and will be located to collect and treat as much parking lot runoff as possible. In
FRCC Larimer Campus – South Parking Lot
October 15, 2013
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addition, we are anticipating utilizing an area between parking for Porous Landscape Detention
for additional water quality treatment. This is in addition to the water quality/detention pond that
will be design with a controlled outlet structure per City of Fort Collins and Urban Drainage
design criteria.
All final computations will be available for reference with the project is complete. Please let us
know if you have any additional concerns with the drainage intent for this project that we should
anticipate incorporating.
As always, we appreciate your assistance and please do not hesitate to call if you have any
questions/comments/concerns.
Sincerely,
JVA, INCORPORATED
By: ____________________________________
Jason T. Claeys, PE, LEED AP
Project Manager