HomeMy WebLinkAboutDrainage Summary & CalculationsPreliminary
Drainage Summary
And Calculations
For:
The Lakes at Towne Road III
Towne Road and 131 Street
Carmel, Indiana
Project #W12-0060
Prepared For:
Indiana Land Development
12070 Abney Run Drive
Zionsville, IN 46077
Prepared By: Andrew T. Miller, E.I.
Certified By: James E. Shields, Jr., P.E.
Date:
27 February 2012
Revised:
14 May 2012
1. Project Description
2. Post Developed Conditions
3. Back Cover Pocket
Existing Conditions Map
Developed Conditions Map
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ENGINEERS
Build rcith i dcrz_.
Preliminary Calculations
The Lakes at Towne Road III
Carmel, Indiana
Job No. W12-0014
TABLE OF CONTENTS
The Lakes at Towne Road III, Shoopman Weihe Engineers, INC.
5/14/2012
1. PROJECT DESCRIPTION
la. EXISTING CONDITIONS
The Lakes at Towne Road III, Shoopman
5/14/2012
WFIHH
ENGINEERS
t'r
,i
The Lakes at Towne Road III
Preliminary Drainage Calculations
The proposed project is located on a 10.102+ acre tract of land located on the West side
of Towne Road, just North of Main Street (131 Street) in Carmel, Indiana. The site is
generally located in part of Section 29, Township 18 North, Range 3 East in Clay
Township, Hamilton County, Indiana with the following UTM coordinates, 86° 12' 18"
W and 39° 39' 58" N.
The pre developed site has been analyzed as three basins. The north basin drains to a
swale along the southern boundary of an existing subdivision known as The Lakes at
Towne Road. The south basin drains to a swale along the eastern boundary of an existing
subdivision known as The Lakes at Hayden Run. The east basin drains to a road side
ditch along Towne Road. All 3 on -site watersheds leave the site at different points but all
drain to the J.W. Brendle Drain. There are no off -site drainage basins that will flow
across the proposed development. See below for runoff rates for the on -site basins:
Weihe Engineers, INC.
Basin South
2 -year
2.016 c.f.s.
10 -year
5.239 c.f.s.
100 -year
14.342 c.f.s.
1. PROJECT DESCRIPTION
la. EXISTING CONDITIONS
The Lakes at Towne Road III, Shoopman
5/14/2012
WFIHH
ENGINEERS
t'r
,i
The Lakes at Towne Road III
Preliminary Drainage Calculations
The proposed project is located on a 10.102+ acre tract of land located on the West side
of Towne Road, just North of Main Street (131 Street) in Carmel, Indiana. The site is
generally located in part of Section 29, Township 18 North, Range 3 East in Clay
Township, Hamilton County, Indiana with the following UTM coordinates, 86° 12' 18"
W and 39° 39' 58" N.
The pre developed site has been analyzed as three basins. The north basin drains to a
swale along the southern boundary of an existing subdivision known as The Lakes at
Towne Road. The south basin drains to a swale along the eastern boundary of an existing
subdivision known as The Lakes at Hayden Run. The east basin drains to a road side
ditch along Towne Road. All 3 on -site watersheds leave the site at different points but all
drain to the J.W. Brendle Drain. There are no off -site drainage basins that will flow
across the proposed development. See below for runoff rates for the on -site basins:
Weihe Engineers, INC.
Basin North
2 -year
1.456 c.f.s.
10 -year
3.252 c.f.s.
100 -year
7.956 c.f.s.
1. PROJECT DESCRIPTION
la. EXISTING CONDITIONS
The Lakes at Towne Road III, Shoopman
5/14/2012
WFIHH
ENGINEERS
t'r
,i
The Lakes at Towne Road III
Preliminary Drainage Calculations
The proposed project is located on a 10.102+ acre tract of land located on the West side
of Towne Road, just North of Main Street (131 Street) in Carmel, Indiana. The site is
generally located in part of Section 29, Township 18 North, Range 3 East in Clay
Township, Hamilton County, Indiana with the following UTM coordinates, 86° 12' 18"
W and 39° 39' 58" N.
The pre developed site has been analyzed as three basins. The north basin drains to a
swale along the southern boundary of an existing subdivision known as The Lakes at
Towne Road. The south basin drains to a swale along the eastern boundary of an existing
subdivision known as The Lakes at Hayden Run. The east basin drains to a road side
ditch along Towne Road. All 3 on -site watersheds leave the site at different points but all
drain to the J.W. Brendle Drain. There are no off -site drainage basins that will flow
across the proposed development. See below for runoff rates for the on -site basins:
Weihe Engineers, INC.
Basin East
2 -year
1.295 c.f.s
10 -year
3.591 c.f.s
100 -year
10.108 c.f.s.
1. PROJECT DESCRIPTION
la. EXISTING CONDITIONS
The Lakes at Towne Road III, Shoopman
5/14/2012
WFIHH
ENGINEERS
t'r
,i
The Lakes at Towne Road III
Preliminary Drainage Calculations
The proposed project is located on a 10.102+ acre tract of land located on the West side
of Towne Road, just North of Main Street (131 Street) in Carmel, Indiana. The site is
generally located in part of Section 29, Township 18 North, Range 3 East in Clay
Township, Hamilton County, Indiana with the following UTM coordinates, 86° 12' 18"
W and 39° 39' 58" N.
The pre developed site has been analyzed as three basins. The north basin drains to a
swale along the southern boundary of an existing subdivision known as The Lakes at
Towne Road. The south basin drains to a swale along the eastern boundary of an existing
subdivision known as The Lakes at Hayden Run. The east basin drains to a road side
ditch along Towne Road. All 3 on -site watersheds leave the site at different points but all
drain to the J.W. Brendle Drain. There are no off -site drainage basins that will flow
across the proposed development. See below for runoff rates for the on -site basins:
Weihe Engineers, INC.
Required Detention
Release Rate (cfs)
Pond Elevation (ft)
2 -year
0.552
903.69
10 -year
0.849
904.24
100 -year
2.107
905.41
Required Detention
Allowable Release Rate (cfs)
2 -year
1.10
10 -year
1.10
100 -year
2.42
Required Detention
124,800
cubic feet
Provided Detention
209,000
cubic feet
The entire site is within of the J.W. Brendle drainage shed thus subject to the following
release rate requirements; 0.1 cfs per acre of development for 0 -10 year return interval
storms and 0.24 cfs per acre of development for 11 -100 year return interval storms.
lb. DEVELOPED CONDITIONS
While there are multiple points of discharge for the site, the allowable release rate based
on the per acre development is the most restrictive and will be used for this development.
The developed site will consist of 12 residential lots, surface streets, sidewalks, and a wet
detention basin. All of the site runoff (along with the developed right -of -way per the City
of Carmel 20 -year Thoroughfare Plan) will be conveyed to a wet detention basin located
near the western boundary line of the proposed development. The proposed discharge
point for this development will be to an existing 36" storm pipe located just west of the
site. If future calculations show that the 36" stoim pipe does not have capacity; an
easement will be obtained to drain south to the J.W. Brendle Drain (to a point where all
of the existing drainage sheds flow).
Modeling:
This analysis was developed to ensure that the proposed drainage system can storm and
convey stonnwater runoff based on the allowable release rates established above. In
order to meet the release requirement, a 6" orifice was set at 903.00 for the 0 -10 year
stoiiir event and a 6" orifice was set at 904.30' for the 100 year storm event. A free flow
model with no tailwater was used to determine the peak release rates and elevation levels.
The emergency overflow weir will be set at an elevation of 905.50 and set along the
westerly bank of the proposed wet pond.
The Lakes at Towne Road II1, Shoopman
5/14/2012
Weihe Engineers, INC.
ICPR, version 3.02, by Streamline Technologies was used to analyze the post developed
site. This program routes and analyzes all components in a storm system on a user
defined time interval. Below is a list of the peak discharges and elevations for the site.
lc. WATER QUALITY
Water Quality for the site will be handled by a wet detention basin located near the
western boundary of the development and storm inlet hoods located at the curb inlets. A
special control outlet structure will be placed on the upstream end of the outlet pipe. This
will hold back the water quality volume allow the sediment to settle and floatables to stay
in the pond.
The Lakes at Towne Road I11, Shoopman Weihe Engineers, INC.
5/14/2012
Stormwater Management Areas
ICPR Calculations (Pre and Post)
Supporting Documentation
The Lakes at Towne Road III, Shoopman Weihe Engineers, INC.
5/14/2012