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Storm Water Drainage Design Calculations
WINDSOR BUILDING
CARMEL CITY CENTER
CARMEL, IN
Prepared for:
Pedcor Companies
770 3rd Avenue SW
Carmel, Indiana 46032
Carmel Redevelopment Commission
30 West Main Street
Carmel, IN 46032
Prepared by:
Circle Design Group
9229 Delegates Row, Suite 150
Indianapolis, IN 46240
(317) 706-2075
November 2021
TABLE OF CONTENTS
Description Page
1.0 Introduction ................................................................................................. 3
2.0 Existing Conditions ...................................................................................... 3
3.0 Proposed Conditions ................................................................................... 3
4.0 Storm Sewer Design ................................................................................... 4
5.0 Conclusion .................................................................................................. 4
Appendix
· Location Map
· Soils Map
· Existing Drainage Areas
· Proposed Drainage Areas
· Storm Sewer Design Calculations
· Emergency Flood Routing Map
1.0 Introduction
A. Scope and Purpose of Project
Pedcor Companies and the Carmel Redevelopment Commission are proposing a
new building south of the Hotel Carmichael within City Center in Carmel, Indiana.
B. Existing Soil Conditions
Soils found within the project limits are classified by the USDA Natural
Resources Conservation Service as follows:
Br – Brookston silty clay loam, 0 to 2 percent slopes
MmA – Miami silt loam, 0 to 2 percent slopes
C. Project Location Map
A project location map is included in the Appendix.
D. State or Federal Water Quality Permits
The project will disturb less than 1 acre of land. Therefore, a Notice of Intent is
not required to be submitted to the Indiana Department of Environmental
Management in compliance with 327 IAC 15-5 (Rule 5).
2.0 Existing Conditions
The site has been previously disturbed as part of adjacent project. Drainage for the site
is generally to the west to an existing 30” pipe within the Monon Trail that drains to an
offsite regional underground detention area that outlets into the Hawkins Regulated Drain
flowing south along the Monon Trail.
3.0 Proposed Conditions
The proposed storm water design will include inlets and pipes that drain to pipes that were
installed during the Hotel Carmichael project and during previous City Center projects.
Calculations for pipe sizing, runoff coefficients and time of concentration are including in
the Appendix.
In addition, emergency storm water routing was designed assumed fully clogged pipes.
The maximum 100-year emergency flood routing water elevation will be at least 0.60’
below the proposed finished floor. A variance has been requested to have it less than 1’
below.
4.0 Storm Sewer Design
The proposed storm sewers were designed based on Chapter 300 of the City of Carmel
Stormwater Technical Standards Manual. The design was performed using the Rational
Method and TR-55 for times of concentration to individual inlets. Unless otherwise noted,
times of concentration were assumed to be the minimum of 5 minutes for individual inlet
basins. Likewise, runoff coefficients were conservatively assumed to be 0.85 for each
inlet. Complete design calculations can be found in the Appendix.
5.0 Conclusion
The project generally meets the requirements of the City of Carmel Stormwater
Technical Standards Manual. No adverse effects to adjacent properties are anticipated
from the development.
Appendix