HomeMy WebLinkAbout02.0 Final Drainage Planr
CIVIL ENGINEERING
June 19, 2013
Garfield County
Building & Planning Department
108 8t St. Suite 401
Glenwood Springs, CO 81601
An Employee -Owned Company
RE: Pioneer Point Subdivision Final Plan Drainage Report
LAND SURVEYING
The subject property is located approximately 3.0 miles north of Highway 82 just east of
Carbondale off of County Road 100. This property owner is proposing the addition of one
new single family primary residence and the creation of 3 medium density lots from the
existing property. The existing guest home within the proposed Lot 3 will become the
primary residence for Lot 3. The existing primary residence within the proposed Lot 2 will
become the primary residence for Lot 2.
The access to Lots 2 and 3 will be via the existing shared driveway. Access to Lot 1 will be
via a gravel driveway on the Hogan property to the north.
The drainage analysis is purely based on the existing conditions because there are no changes
to the surface conditions being proposed in the subdivision improvements. We utilized the
TR -55 graphical method to determine the anticipated run-off The delineated off-site/on-site
drainage basin that would be affected by any Lot 1 changes is approximately 37.91 acres in
size (see exhibit EXDR). This entire basin is collected in either the County Road 100 roadside
swale of the irrigation ditch to the east of County Road 100 and directed into an existing 18 -
inch culvert located just north of the Lot 2/3 shared driveway access. The 100 -yr storm event
was used in determining the peak discharge of the site which was calculated at 8.29 cfs.
The construction of the access and residence on Lot 1 will prompt another evaluation of the
drainage run-off. Based on the development plans of the envelope, a determination will be
made as to whether the run-off is significantly increased. The lack of any subdivision
improvements, however remove the need for any detention on-site. The existing 18 -inch
culvert is sufficient to handle flows from this basin as well as irrigation water.
1517 BLAKE AVENUE, SUITE 101
GLENWOOD SPRINGS, CO 81601
970.9458676 • PHONE
970945-2555 • FAX
W W W.HCENG.COM
VICI\ITY MAP
SCALE: 1" = 4000'
HIGH COUNTRY ENGINEERING, INC.
14 INVERNESS DRIVE EAST, STE F-120, ENGLEWOOD, CO 80112
PHONE (303) 925-0544 FAX (303)925-0547
1517 BLAKE AVENUE, STE 101, GLEN WOOD SPRINGS, CO 81801
PHONE (970) 945.8876 FAX (970) 945-2555
WWW.HCENG.COM
ESHELMAN
GARFIELD COUNTY, CO
PIONEER POINT SUBDIVISION
VICINITY MAP
EXHIBIT #1
DRAWN BY:
DRD
SCALE:
1"=4000'
CHECKED BY:
TJS
PROJECT No:
2031070.00
DATE: PAGE:
8.08-12 1
FILE: J:/SDSKPROJ/206/ 1 070/DWG/VICIN(TY.DWG
87—Morval—Tridell Complex, 12 to 50 percent slopes. Morval—Tridell Complex is a a deep, well drained soil on
alluvial fans, having rapid permeability, medium to rapid runoff, and moderate to high potential for water
erosion hazard.
HIGH COUNTRY ENGINEERING, INC.
14 INVERNESS DRIVE EAST, STE F•I20, ENGLEWOOD, CO 80112
PHONE (303) 925.0544 FAX (303) 9280547
1517 BLAKE AVENUE, STE 101, GLENWOOD SPRINGS, CO 81601
PHONE (970) 945.8876 FAX (970) 9452585
WWW.HCENG.COM
ESHELMAN
GARFIELD COUNTY, CO
PIONEER POINT SUBDIVISION
SOILS MAP
EXHIBIT #2
DRAWN BY:
DRD
SCALE:
1"= 1000
CHECKED BY:
TJS
PROJECT No:
2071060.00
DATE:
8-08.12
PAGE:
1
FILE:
J:/SDSKPROJ/ 207 / 1 060/DWG/ IXHIBRS/SCS MAP. DW G
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ROGER ESHELMAN
GARFIE:LD COUNTY. COLORADO
PIONEER POINT SUBDIVISION
PRELIMINARY EXISTING
DRAINAGE
HIGH COUNTRY ENGINEERING, INC
1517 BLAKE AVENUE, STE 101.
GLENWOOD SPRINGS, CO 81601
PHONE (970) 9458676- FAX (970) 9452555
W W W.HCENG.COM
NO DATE
REWSION
BY
BOE
CENTER OFC�OLO0RRADO
1.800922-1987
OR 534.06700 IN METRO DENVER
CALL 29USINESS DAYS IN ADVANCE
BEFORE VOU DIG GRADE, OR
EXCAVATE FOR INE MARRING OF
UNDERGROUND MEMBER UTLP1ES
•
EX181N. CULVERT 100yr - 24hr
Culvert Calculator
All calculator output should be verified prior to design use
Entered Data:
Shape Circular
Number of Barrels 1
Solving for Headwater
Chart Number 1
Scale Number 1
Chart Description CONCRETE PIPE CULVERT; NO BEVELED RING
ENTRANCE
Scale Description SQUARE EDGE ENTRANCE WITH HEADWALL
Overtopping Off
Flowrate 8.2900 cfs
Manning's n 0.0240
Roadway Elevation 7011.0000 ft
Inlet Elevation 7009.1100 ft
Outlet Elevation 7006.2900 ft
Diameter 1.5000 ft
Length 38.0000 ft
Entrance Loss 0.0000
Tailwater 1.5000 ft
Computed Results:
Headwater 7010.9715 ft Inlet Control
Slope 0.0742 ft/ft
velocity 8.9227 fps
Messages:
Inlet head > Outlet head.
Computing Inlet Control headwater.
Solving Inlet Equation 26.
Solving Inlet Equation 28.
Headwater: 7010.9715 ft
Page 1
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r
100yr - 24hr
Graphical Peak Discharge method
Given Input Data:
Description
Rainfa 1 distribution
Frequency
Rainfall, P (24 -hours)
Drainage area
Runoff curve number, CN
Time of concentration, Tc
Pond and Swamp Areas
Computed Results:
Initial abstraction, Ia
Ia/P
Unit peak discharge, qu
Runoff, Q
Pond and swamp adjustment, Fp
Peak discharge, qp
Type II
1 year
0.2600 in
37.8100 ac
41
26.7573 min
0.0000 % of Area
2.8780 in
0.5000
241.1203 csm/in
0.5822 in
1.0000
8.2939 cfs
Page s