Project Title: Replace Dennis Pond Drain (FFS #R1GN)

State: Oregon

Project Description: The U.S. Fish and Wildlife Service, an agency of the Department of the Interior, has overseen the completion of a facility improvement project at the Tualatin River National Wildlife Refuge as part of the American Recovery and Reinvestment Act. The project was funded using $41,912 in stimulus dollars.

Northern Management Services, a maintenance and construction company based in Sandpoint, Idaho, used the funds to remove and replace more than 300 feet of failed 12-inch drain line at the Refuge’s Dennis Pond in order to restore proper function of the storm water retention system, and mitigate erosion of the Dennis wetland slope.

“This work directly supports the mission of the Refuge in the conservation of floodplain wetlands used by thousands of migrating and wintering waterfowl,” Tualatin River NWR Manager Ralph Webber said. “The rehabilitation of this drain pipe restores filtering functions of the retention pond to protect a large floodplain wetland from sediments and direct storm water runoff.”

Constructed in 1974, the Dennis Pond captures winter storm water runoff and drainage and releases the water into the Dennis wetland through the drainage pipe. A 2001 assessment found the drain line to be in fair condition, but a more recent assessment found the entire length of the drain line had failed.

The company will replace and remove 300 feet of failed 12-inch drain line at Dennis Pond to restore proper function of the storm water retention system and stop erosion of the Dennis wetland slope. Constructed in 1974, the Dennis Pond captures winter storm water runoff and drainage at refuge headquarters and releases water into the Dennis wetland through an underground 12-inch drain line. A 2001 assessment found the drain line in fair condition, but a more recent assessment found the entire length of drain line had failed.

Without the drain, the entire bank of the Dennis wetland slope had failed and was eroding into the wetland. With the new Dennis Pond drain functioning properly, it will protect 30 acres of seasonal wetlands and 3 acres of forested wetlands from sediment loading and petroleum based pollutants. This will help maintain healthy populations of 7,000 migrating & wintering waterfowl, 50 migrating shorebirds, 3-5 migrating and breeding waterbirds, 50 breeding neotropical landbirds, and 500-1,000 resident reptiles and amphibians.

Photos:

Workers lay piping.

Workers seed native grass on recontoured dike.

New piping is put in place prior to assembly.

A section of the drain area after piping was buried.

Originally posted 11/23/2009
Updated 07/22/2010
Page Completed 04/04/2011