Policies
The City of Lenexa is included in a group of communities with populations greater than 10,000 that are federally required to obtain a Municipal Separate Storm Sewer System (MS4) permit for managing nonpoint source pollution in stormwater.

Phase II of the National Pollutant Discharge Elimination System (NPDES) permitting process requires cities, such as Lenexa, to file a Phase II NPDES permit with the Kansas Department of Health and The Environment (KDHE), addressing all the requirements of the permit.

To meet these requirements, Lenexa created its Rain to Recreation stormwater management program that integrates environmental concerns, economic vitality and citizen needs to control and reduce stormwater pollution.

NPDES permit
Lenexa’s permit details the limits, requirements and other conditions necessary to meet state and federal requirements. The city reports its efforts to KDHE on an annual basis.

Stormwater management plan
The plan guides the city in designing, funding and implementing a comprehensive program for addressing current and future regulatory requirements for managing stormwater runoff, flooding problems and natural resources.

City ordinances
Illicit Discharge and Detection
This ordinance specifically prohibits the discharge of pollutants into the city’s storm drain system. Restrictions and regulations within the ordinance are intended to protect the health and safety of citizens, preserve the economic and ecological value of existing water resources and to comply with the city’s NPDES permit.

Land Disturbance
Lenexa’s Land Disturbance Ordinance establishes the city’s process to control erosion, sedimentation and damage caused to water quality from construction-related or other soil disturbing activities. Development is also subject to the city’s Erosion and Sediment Control Design Criteria, as part of the ordinance. The city also utilizes its Erosion and Sediment Control Manual to define erosion and sediment control Best Management Practices (BMPs).

Stream Setback
Setbacks allow streams to function and adapt more naturally while effectively addressing issues such as flooding, habitat protection and water quality. The ordinance creates buffer zones that determine legal uses, protecting natural resources and creating recreational opportunities.

Stream type and stream order serve as the criteria upon which stream setback distances were based. The Western Lenexa Stream Type Map, incorporated in the ordinance as Exhibit A, indicates stream type and order information to be used in the determination of stream setback requirements.

Stream setbacks are composed of three buffer zones on both sides of the stream: the Streamside Zone (25 feet in width), Middle Zone (variable width) and Outer Zone (25 feet). Permitted uses vary from most restrictive in the Streamside Zone to least restrictive in the Outer Zone. An example application of the Stream Setback Ordinance is depicted in the Stream Corridor Zones graphic. This particular application depicts a publicly owned corridor with trails. The corridor may remain in private ownership, but development and use restrictions still apply.

Transfer of Development Rights
Private property can be acquired by the city to protect stream corridors, so Rain to Recreation’s crew manage the stream setback zones to protect water quality, rather than leaving it to private individuals or home owner associations. Details are found in the ordinance’s Subsection F: Modification of Open Space, Density and Setback Calculations.

Design standards
Lenexa adheres to the stormwater design standards and specifications created by American Public Works Association for the Kansas City metropolitan area. These standards link stormwater quantity and quality to engineering practices, addressing infrastructure and conveyance as well as the rainfall events that create stormwater runoff through BMPs.

Pollution prevention plan
Lenexa is required to develop and implement an operation and maintenance program that prevents and reduces polluted runoff from municipal operations.

Questions?
View frequently asked questions about flooding, stormwater and other topics.