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Do you have an agricultural field with poor drainage? King County’s Agricultural Drainage Assistance Program (ADAP) can help. ADAP helps agricultural property owners improve drainage of their agricultural lands by providing both technical and financial assistance. 

In 2011, King County, the Washington Department of Ecology, and the Washington Department of Fish and Wildlife (WDFW) agreed on a set of best management practices (BMPs) that allow most ADAP projects to be performed with just one permit. The streamlined permit process means that a property owner in an Agricultural Production District can comply with all local, state, and federal requirements for maintaining an agricultural waterway by having an approved farm plan prepared in conjunction with the King Conservation District (external link), following the ADAP BMPs and obtaining just one permit, a Hydraulic Project Approval (HPA) from WDFW, a free permit for agricultural drainage projects. 

The ADAP has developed BMPs for addressing four of the most common impacts to agricultural drainage:

The BMPs required to perform an ADAP project are summarized and depicted in the Manual of Best Management Practices for Maintenance of Agricultural Waterways in King County . 

The ADAP developed a classification system for agricultural waterways which is one of the key components of the streamlined permit process for maintaining agricultural waterways.  The waterway classification determines which BMPs are required for a waterway maintenance project. King County classified the waterways in the five Agricultural Production Districts:

Waterways outside the Agricultural Production Districts will be classified as needed. 

For questions about the Agricultural Drainage Assistance Program or ADAP, please contact Lou Beck in the King County Stormwater Services Section.