The Bertrand Creek watershed is one of many of watersheds delineated by the WRIA 1 Project. It is named after its primary hydrologic feature, Bertrand Creek.  The Bertrand Creek watershed straddles the U.S. and Canada border and was chosen as a pilot project by the WRIA #1 Planning Unit for several reasons including relatively homogeneous land use and the presence of large landowners with a relatively sophisticated understanding of the responsibilities and risks related to the ESA, the CWA, and water rights.

The WID is an irrigation district which was formed in 2003 under Chapter 87.03 RCW by the local agricultural community in order to have a local organization that could implement the actions of the Bertrand Management Plan, including engaging into agreements with state and federal agencies. The WID includes all land parcels within the U.S. portion of the Bertrand Creek watershed that are at least 2.5 acres, except for tax-exempt parcels and parcels within the City of Lynden. The WID represents 348 property owners with acreage ranging from 2.7 to 466.4 acres.