Drainage network analysis and improvement plan

Addressing drainage on a systematic basis, rather than parcel by parcel, was one of the key reasons the WID was formed. Farmers and landowners have a difficult time navigating the complex and expensive permit process. The WID addresses drainage by working with agency partners to evaluate drainage problems, design solutions, and identify funding sources to make the solutions feasible.

In the first major step to comprehensive drainage improvement, and with funding from the Flood Control District, Northwest Hydraulic Consultants conducted a network drainage analysis to identify problems and develop a prioritized drainage recovery plan. One key task was dividing the WID into hydrologic units, and the second was to use several data sources to identify wetness levels. This allowed the WID to develop a prioritized list of drainage basins to begin work. During the August board meeting, the board directed staff to begin planning in the top three to six basins. Erin Ericson and Northwest Hydraulic Consultants, with the help of King County ADAP staff, have been conducting fieldwork and are in the process of developing plans for the top three basins.

  • Click here for an overview map of the sub-basins.
  • Click here for a detailed map (large file) of the sub-basins.
  • Based on a combination of wetness indicators, the top six priority basins are (see maps in links above for information on basin numbers): 56, 9, 1, 4, 7, and 6.

Contact WID staff, Erin Ericson, erin@svwid.com, or Cynthia Krass, cynthia@svwid.com, or call us at 425-549-0316, for more information.