HomeMy WebLinkAboutMEYERS SUBDIVISION FEBRUARY 27 2019 MEMO - FDP190006 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE RELATED DOCUMENTKEEFE CIVIL, LLC
825 Union Street
Golden, Colorado 80401
(970) 215-6808
February 27, 2019 Keefe Civil Project Number: 2018-025
Dan Mogen, EI, CFM
Development Review Engineer
Stormwater Engineering & Development Review Division
City of Fort Collins Utilities
700 Wood Street
Fort Collins, Colorado 80522
RE: 2200 Kechter Road Drainage Memo for Residential Permit Application
Dear Dan:
The purpose of this letter is to address the drainage impacts to the existing 2.21 acre residential
lot at 2200 Kechter Road due to the proposed site improvements (Exhibit A – Utility, Grading and
Drainage Plan). The site is located 0.1 mile east of South Timberline Road, on the north side of
Kechter road, and is bound by urban estate residential properties to the west, north, and east.
The existing site is a developed urban estate residential lot with two residential homes, a gravel
driveway, two existing water wells, and several outbuildings. Per the flood insurance rate map
(Exhibit B), the lot is located within Zone X. Zone X is defined as an area of minimal flood hazard
and does not have a base flood elevation associated with it. The local topography generally
slopes from the south to north behind the existing right-of-way fence. The total existing impervious
area is 14,577 square feet (sf).
The proposed grading and drainage design for the site (Exhibit A) follows the existing drainage
patterns. The total impervious area will increase slightly to 15,078 sf and, based on the proposed
design, it is my professional opinion there will be no adverse impacts to downstream properties.
Hardscape or Hard Surface Historic Area (sf) Developed Area (sf)
Change in Impervious
Area (sf)
Asphalt, Concrete 100 805
Rooftop 4,917 6,717
Compacted Road Base 0 3,758
Gravel 9,560 3,798
Total Impervious Area 14,577 15,078 501
2200 Kechter Road Drainage Memo Keefe Civil Project No.: 2018-025
Page 2 of 2 February 27, 2019
Based on these calculations resulting in less than 1,000 sf of additional imperviousness with the
proposed improvements, Keefe Civil respectfully requests no detention and water quality
requirements be imposed on this development.
The future pole barn is not to be constructed with this phase of improvements. At this time, the
area of proposed disturbance is equal to 9,750 sf.
Area of Disturbance
New Concrete Driveway 705
New Rooftop 3,452
New Compacted Road Base 3,758
Ex Building Demolition 2,540
Total 9,750
Thank you for the opportunity to submit this drainage memo. Please do not hesitate to reach
out to me if you have any questions or comments regarding the above items. (970) 215-6808
Best regards,
Megan L. Keefe, PE / Manager
Keefe Civil, LLC
Attachments:
Exhibit A – Utility, Grading and Drainage Plan
Exhibit B – National Flood Hazard Layer FIRMette
Cc: Adam Meyer
Kim Rose
X
X X X X X X
X X X X
X X X X
X X X X X X X X X X X X X X
X X
X X X X X X
X X
X
X X
X X
X
X X X X X X X X X
X
X X X
X X X X X X X
X
X X
X X X X X X
X
X X X X X X
X
X X X X X X X X X X
X X X
X
X X X X X X X X X X
FORT COLLINS, COLORADO
SHEET
MEYER SUBDIVISION
KEEFE CIVIL, LLC
825 UNION STREET
GOLDEN, CO 80401
(970) 215-6808
MEG@KEEFECIVIL.COM
1 OF 1
UTILITY, GRADING AND DRAINAGE PLAN
CONTACT INFORMATION:
KIM ROSE
ROSE CUSTOM HOMES, LLC
3147 TWIN WASH SQ.
FORT COLLINS, COLORADO 80528
(970) 226-1241
KIM@RCHLLC.NET
EXISTING IMPERVIOUS AREA:
ROOFTOP 4,917 SF
CONCRETE 300 SF
GRAVEL DRIVEWAY 9,560 SF
TOTAL 14,577 SF
NEW IMPERVIOUS AREA:
ROOFTOP 6,717 SF
CONCRETE 805 SF
COMPACTED ROAD BASE 3,758 SF
GRAVEL DRIVEWAY 3,798 SF
NEW TOTAL 15,078 SF
CHANGE IN IMPERVIOUS AREA = + 501 SF
ABBREVIATION LEGEND: GRADING NOTES:
1. TOP OF FOUNDATION MUST BE AT LEAST
6" ABOVE THE HIGHEST GRADE
SURROUNDING THE STRUCTURE.
2. THERE MUST BE A MINIMUM GRADE OF
USGS The National Map: Orthoimagery. Data refreshed October, 2017.
National Flood Hazard Layer FIRMette
0 250 500 1,000 1,500 2,000 Feet
Ü
105°2'32.52"W
40°30'46.53"N
105°1'55.06"W
40°30'19.17"N
SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
HAZARD SPECIAL AREAS FLOOD
Without Zone A, V, Base A99 Flood Elevation (BFE)
With BFE or Depth Zone AE, AO, AH, VE, AR
Regulatory Floodway
0.of 2% 1% Annual annual Chance chance Flood flood with Hazard, average Areas
depth areasdrainage of less less than than one one foot square or with mile
Zone X
Future ChanceAnnual Conditions Flood Hazard 1%
Zone X
Area Levee.to with See Reduced Notes. Flood Risk due
Zone X
Area with Flood Risk due to LeveeZone D
NO SCREEN Area of Minimal Flood Hazard Zone X
Area of Undetermined Flood Hazard Zone D
Channel, Culvert, or Storm Sewer
Levee, Dike, or Floodwall
Cross Sections with 1% Annual Chance
17.5 Water Surface Elevation
Coastal Transect
Coastal Transect Baseline
Profile Baseline
Hydrographic Feature
Base Flood Elevation Line (BFE)
Effective LOMRs
Limit of Study
Jurisdiction Boundary
Digital Data Available
No Digital Data Available
Unmapped
This digital map flood complies maps if with it is FEMA's not void standards as described for the below. use of
The accuracy basemap standards shown complies with FEMA's basemap
The authoritative flood hazard NFHL information web services is derived provided directly by FEMA. from This the map
was reflectnot exported changes on or 2/amendments 19/2019 at 1:subsequent 56:49 AM to and this does date and
time. becomeor The superseded NFHL and effective by new data information over time. may change
This elementsmap map image do not is appear: void if basemap the one or imagery, more of flood the following zone labels,
legend, FIRM panel scale number, bar, map and creation FIRM effective date, community date. Map identifiers,images for
unmapped regulatoryfor purposes. and unmodernized areas cannot be used
Legend
OTHER FLOOD AREAS HAZARD OF
OTHER AREAS
STRGUECNTUERREASL
FEATURES OTHER
MAP PANELS
8
1:6,000
B 20.2
The point pin selected displayed by the on the user map and is does an approximate not represent
an authoritative property location.
5% AWAY FROM THE STRUCTURE WITHIN
THE FIRST 5 TO 10 FEET ADJACENT TO
THE RESIDENCE.
3. ALL SLOPES MUST MEET THE MINIMUM
REQUIREMENT OF 1% AND ARE NOT TO
BE STEEPER THAN 33% (3:1).
LEGEND:
PROPOSED BUILDING
TOF = 4948.60'
KECHTER ROAD
FUTURE SAGE CREEK ROAD
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2.15
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