Digging into Overland Park’ Stormwater Management

Tuesday (May/8), I went to Overland Park (OP) city hall to meet with Lorraine Bassalo and her colleague who work as civil engineering in stormwater division under public work agency. We met to learn on how OP manage their stormwater quality. Lorraine started the discussion with describing, why OP is way ahead than other city in stormwater management. Since the beginning on establishment wastewater treatment plant (WWTP), OP government decided to separate the sanitary and stormwater sewerage. At the same time, Kansas city (Missouri) decided to have one pipe system which collects sanitary and stormwater. The basic idea of the system is when there is overflow, they would diverts and directly discharge into the river (untreated). Dilution is expected to reduce the concentration of the contaminant (nutrient, bacteria). But after Clean Water Act (CWA) in the 1970s, it was found that the dilution scheme doesn’t work out. Now, the system is somehow almost unmanageable and they’re working on to increase the capacity of its WWTP.

OP map


Do OP have resident who doesn’t connect to their wastewater pipe? Yes, but only a small percentage – about 100 houses don’t connect to it and have their own septic tank. This happens because of 2 things: (1) old houses; (2) the land where they build it don’t have enough slope/ gravity to connect to the system. The new one should connect to the piping system. For OP, the WWTP and water treatment plant (WTP) service is hold by Johnson County (JoCo). While the city would have to manage their stormwater. The goal for the OP stormwater management is no flooding and good water quality of natural waters (creeks and/ rivers).

OP signed permit engagement with Kansas Department of Health and Environment (KDHE), where allows OP to discharge the stormwater into natural system (rivers and/creeks). This permit also resulted in responsibility to maintain the water quality is in good quality. To ensure the good water quality, the permit also requires OP to implement 4 program:

  1. Public education and involvement. The city  sticks sticker and/ placard with fish sign on it, as information for the community and increase their awareness for what they will discharge into the stormwater sewerage for its will flow into the river and impacts the fish. Volunteer help the city to stick the sticker/ placard on the sewerage
  2. Illicit discharge control. The example for this is when there is resident/ developer who spill or discharge the paints or oil into the stormwater drainage. City will inform,  and enforce the resident/ developer if they caught red handed to mitigate and paid the tickets. On other case where they can’t find the suspect, the city will send leaflets to the resident with the hope that next time there is incident, the resident will inform the authority
  3. Construction and Post construction runoff controll. It only apply for the new development (after 2004), that they need to take certain practice to reduce excessive sediment go to the creek(s).
  4. New development have to treat their stormwater before discharge into the stormwater sewerage by green infrastructure (rain garden, bio-swale, etc).

To maintain the quality of their stormwater and increasing public participation, OP runs one of JoCo program called cost-sharing stormwater treatment program. I’ve got the application brochure in Lenexa’s farmer market. JoCo provides 10,000 USD/year/city to run the program. The co-funding program is a 50/50 funding  green infrastructure with a cap of 1,000 USD for rain garden. If you installed rain garden/ barrel and it cost you about 200 USD, city will reimbursed 100 USD. If you build rain garden about 4,000 USD, then the city will reimburse you 1,000 USD. The program scheme are: (1) resident apply for the program and provide the design which using native plant; (2) city reviews the design and approve it; (3) resident builds it and send the receipt; (4) the city inspects and agreed on it and then reimburse based on the program. For OP, the number of applicant since the program was launched in 2011 was 20 applicant with average total funding 2,000 USD/year. Lorraine stated that involving public in the program is the most challenge one, for them to fully participate in a program and responsible in the maintenance while they’re busy with their work life. To increase the participation, Lorraine sends newsletter (twice a year) which informs the resident about the program.

Discussion with Lorraine and her colleague on stormwater management

Do OP have water quality problems, yes they do. KDHE stand that 3 creeks in OP have impaired water quality.  They are Wolf and Coffee creek is high in sediment, nutrient, and bacteria, while Tomahawk creek is high in bacteria. It is predicted that the cause of it is normal activity in city. City have a regular monitoring which is done by United States Geological Survey (USGS) which is being appointed by KDHE. USGS take sample 4 times/year – an hour of the peak of the storm. The purpose is to get the same rain level among the sampling sites. The sampling is done in bare minimum standard, but Lorraine struggle to interpret  correlation among the sites. As Lorraine struggles with it, she approach USGS for a new proposal. USGS recommend OP to rotating the sampling site and co-funding the sampling activities. In addition to it, Lorraine is hoping for adding more sampling sites; perform their own monitoring (online and offline sampling). To reduce the pollution input/ load from stormwater runoff, OP issued stream corridor ordinance.

Another challenging things that Lorraine notice is to convince the council to put investment on improvement of water quality (100,000 USD/year for 5 years), coordinating inter and intra-organization, and enforcing the regulation while there is a lot of other interest (economic development is one of it) is going on. She is also hoping for  county plan in building watershed partnership/ board which based on watershed management is happening sooner. For it would help city to overcome problems such as water quality without administration border but as a creek/ river.


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