By Don Behm - Milwaukee Journal Sentinel
The last unprotected reach of Trinity Creek close to its headwater springs in Mequon will be relieved of a recurring burden of soil and agricultural pollutants now that it has been acquired by the Mequon Nature Preserve.
To ensure the 6.38-acre property west of busy Wauwatosa Road is not developed in the future, the Milwaukee Metropolitan Sewerage District has proposed paying $50,000 to the nature preserve to create a permanent conservation easement on the property deed that prohibits subdivision and building construction.
Not to stop there, the easement would require restoration of native grasses and trees on the land.
The easement would allow one change to the landscape. The Mequon Nature Preserve could shift the flow of the creek through the roadside property out of a straightened agricultural drainage ditch and into a more natural, meandering channel, said David Grusznski, Milwaukee program manager for The Conservation Fund.
MMSD proposed acquiring the easement for its Greenseams flood management program so the low-lying property would remain available to store floodwater and the conservation measures would improve the creek's water quality, Grusznski said. The Conservation Fund administers Greenseams for MMSD.
Replacing the ditch is a top priority for the nature center, Mequon Nature Preserve Executive Director Kristin Gies said. A more natural stream channel would provide "more effective fish passage" upstream, she said.
"We've been dying to do this," Gies said. She described the ditch as "a cork in the creek's fish habitat."
"It's a challenge for fish to get through that ditch," she said.
A few northern pike from the Milwaukee River have made it through the shallow ditch to spawn in upstream ponds and wetlands at the nature preserve. Groundwater bubbles to the surface in natural springs that flow into the ponds and form the headwaters of the creek.
More fish of all sizes would be able to reach the ponds and adjacent wetlands if they get rid of the ditch, Gies said.
Greenseams already has preserved streambank properties on both sides of the small parcel, Grusznski said.
MMSD owns an easement on 26 acres to the west that encompasses the ponds and wetlands near the preserve's PieperPower Education Center.
In 2009, the district purchased 26 acres of Trinity Creek floodplain immediately east of Wauwatosa Road. A few years earlier, the district acquired an adjacent 40-acre parcel of floodplain farther east.
This easement will complete protection of the entire upstream end of Trinity Creek, from its headwaters downstream to within a stone's throw of the Lilly Lane Nature Preserve off Baehr Road, Grusznski said.
The MMSD commission this month will act on the district staff's request to purchase the easement for $50,000. The commission's policy and finance committee will consider the proposal Monday.
Mequon Nature Preserve purchased the 6.38-acre parcel in late November from K&L Trust LLC, Gies said.