Oasis Car Wash Basin Retrofit

Oasis pre-const 3-28-14 005
The City partnered with Oasis Kwik Carwash to retrofit this retention basin on Jiffy Street
part of the 319 grant, the Dry Branch Watershed Project.

The Problem

Detention basins help control excess stormwater runoff. Unfortunately, with its proximity to Highway 70 and Wentzville Parkway this basin had ongoing maintenance issues.  It often filled with litter and debris, blocking the storm drain and preventing proper drainage. This led to stagnant water which attracted mosquitoes and other unwanted pests. The area collected so much debris that staff filled a 55-gallon drum with trash when it is cleaned every two weeks. The basin was also often polluted with auto fluids that ran off the pavement from nearby roadways. This not only affected local wildlife but, could also contaminate groundwater supplies as it soaked into the ground.  

The Solution

The detention area was expanded and reconfigured to be a bioretention basin, or rain garden, which uses plants and soil to filter pollution. Vegetation is selected to help screen trash and allow for easier maintenance. Curbs along the pavement were removed to allow drainage to spread out through a rock channel, then drain into the bioretention more slowly. This helps reduce erosion and improves infiltration.

Before and After

 Oasis Passive Stage Samplers 5-29-14 010  Oasis Passive Stage Samplers 5-29-14 007
Before construction:  The photo on the left shows trash that accumulated and  
water sampling equipment used to test water quality. 
 Oasis Carwash Basin Retrofit  Oasis Carwash Basin Retrofit 2 
After construction:  Pavement runoff flows through curb cuts.  Soft rush and black-eyed susan
plants easily adapt to wet and drought conditions and help filter runoff water. 
This project is funded by US EPA Region 7 through the Missouri Department of Natural Resources subgrant number G11-NPS-07.


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