with gallery: Controversial restoration of Malletts Creek 'substantially complete'

The county drain is the main outlet for stormwater runoff from the city of Ann Arbor and dumps into the Huron River. After phosphorus loading into the river caused numerous ecological problems - including algal blooms - state officials declared the need for remediation.

Washtenaw County officials gave project managers from the Michigan Department of Environmental Quality a tour Tuesday morning at the work sites on the creek south of Washtenaw Avenue near Platt Road and the Washtenaw-Stadium split.

Drain Commissioner Janis Bobrin and her Environmental Manager Harry Sheehan escorted Karol Patton, senior project manager for the Malletts Creek work, as well as DEQ project managers Karen Nickols and JoAnn Kalemkiewicz through three sites where the majority of the work had been done.

Work began in September to prevent stream bank erosion and lessen the flow of sediments along 1.5 miles of the waterway as a part of an overall plan to decrease phosphorus loading into the Huron River, as a part of a DEQ mandate.

The plan, approved in 2000, did not account for the ban on phosphorus fertilizer imposed by the city of Ann Arbor in 2006. Improvements to Mary Beth Doyle Park, completed in 2008, effectively reduced 25 percent of the phosphorus in Malletts Creek, Sheehan said.

The $2.8 million project is funded by a grant from the DEQ and a revolving loan from the state -- which will be paid back at a 2.5 percent rate over 20 years using funds from the stormwater portion of city of Ann Arbor water bills, Sheehan said.

Mead Bros. Excavating, which secured the contract for much of the work done on the project, suffered a blow in December when an accident left an employee dead. The small company - of which many of its employees are related - was rattled after Wayne Mead was pinned by an excavator while working on the restoration at the County Farm Park on Platt Road.

Though initial reactions from area residents at public meetings held on the project were negative, Bobrin said she believes public perception has turned around.

“This park was a hidden gem,” Bobrin said.

Embankments that were once steep - causing a narrow, fast flow in the drain that swept sediment straight into the river - are now more gradual.

Non-native tree species and acres of invasive honeysuckle bushes have been removed. Willow and dogwood cuttings have been planted along the banks of the drain.

Sections of the drain have been bolstered with rock, and diversions have been created to prevent further erosion of embankments.

Sheehan said the way the water is now flowing through the creek bed is promising - the current is carving a new route through the channel, depositing once-troublesome sediment.

Diversions have been created in the creek bed to structure the flow of the current for a portion of the drain by Exmoor Road in a residential neighborhood where homeowners watched their rear property lines erode into the drain.

Instead of sending water into the severe bend of the creek where it would carve away sediment and carry it downstream, bands of large boulders - termed “rock veins” - channel the water into the center of the creek.

Part of the drain at the County Park has been engineered to be a new, three-acre storm water detention wetland that will collect sediment once it is fully operational. While newly planted vegetation takes root, a steel wall will keep water out of a lowland.

Within several years time, Sheehan said the wall would be cut open to allow water to flow into the area.

The wetland is designed to collect sediment in one of its first pools - which will require periodic dredging, Sheehan said.

The sediment collection basin is part of the overall efforts to keep dirt - which contains phosphorus - out of the Huron River.

“These creeks existed way before parking lots and developments existed,” Bobrin said. “We’re trying to redesign creeks so they can become the best creeks they can.”

A native seed mix has been spread across the restored area at the County Park adjacent to Washtenaw Avenue where the wetland has been created.

A new pedestrian access point to the County Park will be created from the multi-use path that runs along Washtenaw Avenue.

Though some complained that the removal of the trees and brush - which Sheehan acknowledged was a clear-cut activity - a prairie has now been created that Sheehan said will be maintained through controlled burns.

Sheehan said regular burns will help keep invasive species out of the prairie.

Along the creek several piles of sand have been placed to serve as turtle habitat.

While there are still minor parts of the restoration project that need to be finished, Sheehan is calling the Malletts Creek work “substantially complete.”