Target Corp. has signed an agreement with the Minnehaha Creek Watershed District to work on new ways to reduce stormwater runoff from two of the company’s properties.

The move is part of a larger, ongoing effort to return the creek to a natural state as much as possible, especially as it flows through developed urban areas in Hopkins and St. Louis Park.

Acres of roofing and pavement line portions of the 22-mile creek that runs from Lake Minnetonka to Minnehaha Falls and the Mississippi River. Rain and snowmelt drain quickly into the creek, carrying leaves, pet waste and other pollutants, said district planner Michael Hayman.

“In urban areas you also see issues with salt and sand, and there’s obviously oil or other chemicals from vehicles,” he said.

Included in the agreement are the Knollwood SuperTarget store and parking lot on 15 acres adjacent to the creek in St. Louis Park, and a Target corporate building and parking lot on 24 acres next to Brownie Lake in Minneapolis, which flows into the Minneapolis Chain of Lakes and eventually the creek.

“We’re not saying that either of these sites is an issue,” said Hayman. “It’s really just an initial investigative phase.”

Target executives signed the agreement, called a memorandum of understanding, on March 7.

It does not require Target to make changes, but “documents mutual goals and establishes a cooperative framework” to explore whether environmental improvements might be beneficial and cost-effective.

“Efforts like this are just one example of Target’s commitment to sustainability,” company spokeswoman Jessica Stevens said in a written statement. She said it’s something to be achieved “by balancing growth with the social, environmental and economic well-being of communities.”

First step: investigation

Under the arrangement, watershed district scientists will spend much of 2013 collecting information about the sites, including how much runoff there is and data about soils and topography. The goal is to identify whether it is feasible to reduce impact on the creek by reducing, collecting or purifying runoff, Hayman said.

Strategies used elsewhere have included underground storage detention, replacing hard surfaces with porous ones and building ponds and vegetative buffers.

Cutting down on flooding

In addition to improving water quality, another goal is to reduce localized flooding and the tendency of the creek to rapidly rise and fall during periods of heavy rain, Hayman said.

Stevens said Target has completed similar projects in Cottage Grove and Lino Lakes, but she did not provide details.

Hayman said Target is one of several partners to work with the watershed district. Methodist Hospital and the cities of Hopkins and St. Louis Park have cooperated in efforts to re-establish natural curves in the creek to slow it down, and to expand municipal parks and open spaces along its banks.

The agreement with Target stipulates that at the end of the project’s first phase, the district will collaborate with the company to discuss conceptual designs for improvements, including what might be feasible in terms of techniques, costs and timing.

If agreement is reached on those issues, projects at the two sites could be implemented in a second phase during 2014 and 2015.