Recent rains and flooding have almost certainly damaged parts of $7 million worth of shoreline, walkway, vegetative and other improvements installed in 2010-11 along Minnehaha Creek from Minnehaha Falls to the Mississippi River.

But officials aren't quite sure about the extent because so much of it remains under water.

"We're all worried about it. We're all concerned what we're going to find as the water recedes," said Cliff Swenson, director of design and program management for the Minneapolis Park and Recreation Board. The board pitched in on the restorations, along with the Minnehaha Creek Watershed District, the Minnesota Veterans Home and the U.S. Army Corps of Engineers.

The improvements in "the glen," a densely wooded, 54-acre corridor where the creek makes its final dash to the Mississippi, included an elevated walkway, reinforcements to walls installed in the 1930s by the Works Progress Administration, installation of natural and manufactured structures to protect shoreline and slow the creek's flow, and an overhaul of woodland plantings, including eradication of invasive species.

Swenson noted that the work was designed to withstand some high water but not the effects of the wettest year to date on record, including the Twin Cities' second-wettest June ever.

Friday brought another inch of rain to the Twin Cities, with most of it falling in one morning hour. That caused the creek at Hiawatha Avenue, just upstream from the falls, to rise more than 9 inches in just over an hour, matching a level from which it had declined two weeks ago.

Stan Schmidt — Star Tribune, Star Tribune
High water flooded the walking and bike paths along Minnehaha Creek on Sunday in Minneapolis.

Park Board environmental management director Deb Pilger walked parts of the glen Thursday, before the recent rain, and said the boardwalk appeared to be in good shape but that erosion was evident. Repair costs could be covered partly by federal disaster funds.

Pilger also noted that the Minneapolis Chain of Lakes, Powderhorn Lake and Lake Hiawatha have hit record levels this year, but she couldn't say exactly how high those have been.

"The gauges are under water," she said.

At the end of June, Lake Calhoun was at its highest level in 131 years of records.

Bill McAuliffe • 612-673-7646