Best Management Practices Research and Development
Nationally, it is becoming common practice to design/construct/implement stormwater/water quality Best Management Practices (BMPs) to improve the quality of stormwater runoff and the quality of water in our streams and rivers. Many studies aimed at evaluating the ability of stormwater BMPs to remove pollutants exist. However, the majority of these studies are located outside of our region where different physical, climatic, and geological conditions exist. Furthermore, inconsistencies in sample collection techniques and laboratory analysis, and incomplete reports of watershed characteristics make it difficult to effectively apply results from these studies to our region.
In cooperation with cities in Johnson County, the Stormwater Management Program co-funds the design, construction and monitoring of stormwater BMPs in an attempt to obtain region specific data on their effectiveness.
Download: 2008 BMP Funding Requirements
Baffle box and hydrodynamic separators-- City of Shawnee
The city of Shawnee recently installed two proprietary BMPS in a residential sub-division. The first BMP is an off-line baffle box system in which stormwater is diverted from the main storm sewer system into a treatment chamber and then re-enters the main storm sewer. The second BMP is an inline hydrodynamic separator which stormwater enters in such a way that induces a gentle swirling flow pattern that enhances gravitational separation. Both BMPs are designed to remove sediment, oil and trash and are sized to treat up to a 1.37 inch rainfall event.
Monitoring of these BMPs began in March of 2006 and ended in June of 2007. Various data were collected during multiple rainfall events as part of this study to quantify the BMPs ability to remove pollutants. These included rainfall, flow, total suspended solids, nitrogen and phosphorous. Data analysis is currently underway and results should be available late 2007.
For more information contact Mike Gregory, City of Shawnee at (913) 631-2500 ext 312 or mgregory@CI.Shawnee.KS.US
Installation of an off-line baffle box system.
Installation of an inline hydrodynamic separator.
Bioretention cells-- City of Overland Park
The city of Overland Park, in cooperation with the Stormwater Management Advisory Council (SMAC), is conducting two projects to study the effectiveness of bio-retention cells to capture and biologically treat storm water contaminants. A bio-retention cell is a soil and plant-based filtration device that removes pollutants from stormwater runoff through a variety of physical, biological, and chemical treatment processes. It also serves as a volume reduction system to reduce stormwater runoff quantity.
One bioretention cell is located adjacent to a new parking lot at Highland View Park near 151st Street and Antioch Road. The bioretention cell is designed to meet the treatment and detention criteria for all or part of the impervious area created by the new parking lot. The bioretention cell at Highland View Park was constructed in the summer of 2007. The second bioretention cell is scheduled to be constructed in fall 2007 at South Lake Park near 87th and Robinson Streets. This bioretention cell also is designed to meet the treatment and detention criteria for all or part of the impervious area created by the new parking lot.
It is the objective of these projects is to address and document the uncertainties in the design of bioretention cell best management practices (BMPs). This includes demonstrating the challenges in design and installation and demonstrating the effectiveness of biocells in detaining the net runoff generated by a 1 to 1.5 inch rainfall event.
The approach of the projects includes:For more information contact Bill Heatherman, Stormwater Engineer, city of Overland Park, (913) 895-6050 or Bill.Heatherman@opkansas.org.
Planting of the bioretention cell at Highland View Park
Porous Pavement Parking Lot at I-Lan Park --City of Leawood
The city of Leawood, in cooperation with the Stormwater Management Advisory Council, is evaluating the effectiveness of a porous concrete parking lot at I-Lan Park located at 126th and Nall. The city will collect and analyze water samples as well as complete site visits during and after rainfall events to record the operation and effectiveness of the BMP. The BMP performance will be rated over a range of hydrologic and hydraulic conditions over a three year period.
For more information contact Joe Johnson, Public Works Director, City of Leawood (913) 339-6700 ext. 130 or joej@leawood.org.
Mize Lake Wetlands—City of Lenexa
The city of Lenexa currently has two constructed wetlands in place that provide water quality treatment for stormwater flowing into Mize Lake, one of the City’s regional stormwater facilities. The wetlands and the lake were constructed in 2004. The use of wetlands as a stormwater treatment facility is fairly limited in this region; however this method of treatment is more prevalent in other areas of the country. The wetlands are designed to treat and hold the water quality storm (1.37 inches for the region) that falls on the entire drainage area directly upstream from the lake. Runoff flows through a pretreatment forbay before entering the wetland. Water flows through a winding path through native wetland vegetation until it is discharged into the lake. Water is permanently ponded throughout the wetland in areas of varying depth. The wetlands are located in sub watersheds of Cedar Creek and both sub watersheds are currently undergoing development. The city is monitoring the runoff as it flows through the wetlands and to the lake to evaluate the wetlands as a best management practice for treating stormwater runoff.
For more information on this project visit http://www.raintorecreation.org/index.html or contact Rob Beilfuss, Water Quality Specialist, City of Lenexa (913) 477-7666 or rbeilfuss@ci.lenexa.ks.us.
Constructed Wetland at Mize Lake
Porous Asphalt Parking Lot—City of Lenexa
The city of Lenexa has constructed a porous asphalt parking lot at the Coon Creek Trailhead near K-7 off of Prairie Star Parkway. Porous asphalt reduces stormwater runoff by allowing infiltration of rainwater through the asphalt. The city of Lenexa is monitoring the quantity and quality of runoff from this BMP to evaluate porous asphalt as a regional BMP.
The BMP is designed to treat and hold the water quality volume storm (1.37 inches) that falls on the lot itself and on the approach road to the lot, which is approximately 200 feet long and not pervious. Runoff runs directly through the asphalt into an aggregate layer under the pavement. Several inches of water ponds permanently and is allowed to infiltrate into the soil. Any additional water is stored temporarily in the gravel layer and is released through an underdrain system.
For more information on this project visit http://www.raintorecreation.org/index.html or contact Rob Beilfuss, Water Quality Specialist, City of Lenexa (913) 477-7666 or rbeilfuss@ci.lenexa.ks.us.
Porous asphalt Coon Creek Trailhead
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JOHNSON COUNTY STORMWATER MANAGEMENT PROGRAM
1800 W. 56 Highway
Olathe, KS 66061
Phone: (913) 715-8333
Fax: (913) 715-2453