Summary
The Cool Creek Watershed drains significant portions of the City of Carmel and the Town of Westfield. The watershed drains approximately 23.7 square miles, with its headwaters near 199th Street. Cool Creek flows south southeast, discharging into the White River south of 116th Street. Tributaries include Hot Lick Creek, Little Cool Creek, Highway Run, Mary Wilson Drain, Osborn & Collins #2 Drain, H. G. Kenyon Drain, and Anna Kendall Drain. US 31 and SR 431 run through the middle portion of the watershed. The Westfield portion of the watershed contains both urbanized areas as well as significant tracts of undeveloped land (primarily agricultural). The Carmel portion of the watershed is fully urbanized. Portions of the watershed lie in unincorporated Hamilton County, but are subject to potential annexation in the future.
Recently, there has been growing interest and concern regarding stormwater design and management practices and their effectiveness in controlling the quantity and quality of stormwater runoff. This issue is of special concern given rapid growth in the Westfield area and pending requirements from the U.S. EPA and IDEM.
New federal regulations promulgated by the U.S. EPA and administered by IDEM require communities to improve the quality of stormwater runoff. Stormwater runoff is a leading source of stream impairment due to pollutants that collect on parking lots, streets, highways, commercial, industrial and residential areas and wash off during rain events. These new regulations will require communities to educate and involve the public on stormwater quality issues, minimize erosion from construction sites, improve the long-term quality of stormwater being discharged from new developments, and develop effective municipal housekeeping operations to minimize stormwater pollution.
Hamilton County, Westfield, and Carmel entered into an agreement in 2001 to complete a thorough evaluation of stormwater management in the watershed. Clark Dietz, Inc. was retained to develop a Cool Creek Watershed Management Plan that includes recommendations to correct existing stormwater problems and prevent future problems from occurring as the watershed continues to develop.
It was important to identify the scope of work for this plan. The focus of the study was on stormwater issues on the main channel of Cool Creek and its major tributaries. There are other isolated stormwater problem areas in the watershed (referred to in this report as “neighborhood” problem areas). Though some of these problem areas were identified and located on problem area maps, detailed analysis and solution development for these areas was beyond the scope of this project.
This project also included an evaluation of water quality issues in the watershed, including a general review of the condition of the riparian corridor, a stream water quality sampling program, an evaluation of streambank erosion problems, a review of water quality violations (NPDES permit related), and an assessment of best management practices in the watershed.