SEATTLE — Construction could begin this fall on interim measures that would restore the Howard Hanson Dam on the Green River to normal flood capacity, the U.S. Army Corps of Engineers said Friday.

The corps said it plans to use $44 million in new federal money to install additional drains to control where water flows, stabilize the spillway and add rock to protect the flood control dam against erosion.

Heavy rains in January 2009 weakened a reservoir wall at the dam, increasing the flood risk downstream in the heavily developed Green River Valley, where about 170,000 people live.

U.S. Sen. Patty Murray said the measures could provide much better protection for communities. She said the economic effects of a flood in the valley would be devastating, with property damage from a severe flood estimated at $3.7 billion.

“This is a big win for our region,” Murray said at a news conference in Seattle where the corps outlined its plans.

She and other congressional leaders lobbied for the money as part of a supplemental appropriations bill that President Barack Obama signed into law Thursday.

Col. Anthony O. Wright, the corps’ Seattle District commander, said a series of filtered drains and other measures would be installed to control water and prevent internal erosion.

“We believe this is the best solution for getting the dam back to full capacity and in a durable fashion,” Wright said.

Temporary repairs have reduced the risk of flooding, but less water can be safely stored behind the dam. The dam’s current capacity is about half what it normally is, Wright said.

The sprawling Green River valley is home to the nation’s fifth largest industrial park with hundreds of warehouses and small manufacturers. Millions of dollars have been spent on flood preparations for homes and businesses, while the corps makes fixes.

“The interim measures will buy us vital time and protect the Green River Valley as we work to put in place a permanent, long-term solution,” said U.S. Rep. Adam Smith.

Pamela Linder, 60, who lives in Tukwila, said she hoped the fix will relieve some of the uneasiness she and others have felt living along the river.

“There was a sense throughout all the community of hopelessness,” she said.