Project Spotlight: Mesa Lake Wetland Restoration

by Tina Blewett, DU Regional Biologist

Mesa Lake Project after restoration, showing new dike and water control structure

Mesa Lake Project after restoration, showing new dike and water control structure

The Columbia Basin of east central Washington is a continentally important area for hundreds of thousands of migrating and wintering waterfowl due to the large river systems, over 670,000 acres of irrigated croplands, and more than 300,000 acres of reservoirs, lakes and wetlands.   Before the 1950’s this area was sage steppe and grassland desert, with annual precipitation averaging 8-9 inches. A massive irrigation project called the Columbia Basin project changed all that. Reservoirs, lakes, and wetlands that historically never existed can be found throughout the landscape. Many of these are on lands available to the public for hunting and other recreation, such as Washington Department of Fish and Wildlife (WDFW) owned or managed lands.

The Mesa Lake restoration project is in the heart of the Columbia Basin, and has been a collaboration between Ducks Unlimited and WDFW for several years. WDFW acquired most of the property from a former duck club, and also manages an adjacent BOR parcel on the lake with a boat launch, so that nearly the entire lake and surrounding wetlands and uplands are managed for wildlife and public access. The Mesa Lake Management Unit is part of the Sunnyside/Snake River Wildlife Area in Franklin County, and totals 715 acres with the lake, pond and wetland habitats comprising 200 of those acres. The property provides multiple biological needs for waterfowl and other birds, such as breeding, wintering, and fall and spring migration. The department has a pivot to provide cornstalk residue and other moist soil plants as important food for migrating waterfowl.

Winter counts have reached 30,000 to 40,000 ducks in the immediate vicinity. Mallards make up the majority of duck concentrations, with pintails, scaup, wigeon, gadwall and teal also present. In early spring, ring-necked ducks, canvasback and redheads are generally found on moist soil units. Canada geese and white-fronted geese frequent the larger lakes/ponds, which have held large numbers of scaup (300-500) in winter. The lake and numerous open water wetlands provide resting habitat for several thousand ducks post-season.

The last phase of restoration construction concluded in August of 2014. These activities included replacement of two failed dikes, installation of a water control structure to allow for better water management and therefore habitat management, and upgrades to an access road. This final phase benefited two wetlands totaling 9 acres in size. The water to these wetlands is supplied year-round by irrigation run-off and seeps, and the water is warm enough that it provides one of the few areas of open water during severe winter weather. Restoration activities performed by DU at this site were funded by a grant through the WA State Migratory Bird Stamp & Artwork Program and with donated DU matching funds.