Where Minnehaha Creek snakes through the west metro suburbs, a mission to mend the strained relationship between the water and the cities that crowd its banks has reached its final phase.

Construction has begun on the capstone of a 15-year series of multimillion-dollar projects by the Minnehaha Creek Watershed District to restore one of the creek's most populous —and polluted — stretches. The water already is significantly cleaner as it flows past Hopkins and St. Louis Park. Soon efforts will focus eastward in Minneapolis – with the goal of getting Lake Hiawatha delisted from the state index of impaired waters.

Past development treated Minnehaha Creek like a glorified drainage ditch, paring its curves and paving its floodplain. The result: Water moving so fast down the creek's artificially straightened channel that it eroded the banks, swamped nearby properties and loaded the lakes of south Minneapolis with nutrients making them increasingly unsuitable for swimming.

To counter the damage, the watershed district has spent millions of dollars to engineer bends back into the creek, build parks and nature preserves, protect a nearby hospital from flooding and convert an eyesore of a warehouse into a colossal housing development that doubles as a regional storm water treatment center.

Each project was designed with water management as the central element around which local governments and developers assembled their plans. In the process, officials say, they also improved blighted corridors, increased housing and even reduced crime.

"When water is meaningfully integrated into land-use decision making, we can realize sustainable benefits that don't just improve the environment but contribute to community and contribute to the economy," said James Wisker, administrator for the watershed district.

Man-made problems

Minnehaha Creek commands a 178-square-mile urban watershed that covers 29 cities and townships in Hennepin and Carver counties, encompassing some of the wealthiest communities in Minnesota. It connects streams, wetlands and more than 100 lakes, including Minneapolis' iconic Chain of Lakes and Minnehaha Falls.

Minneapolis residents in 1967 petitioned to form the Minnehaha Creek Watershed District, a regional taxing authority responsible for tackling issues around flood protection and water management.

But individual property owners, developers, cities and park commissions control what happens on land, making for an intrinsic tension. What happens on the land impacts the water, and what one community does to alter wetlands invariably affects those who live downstream.

Between Hopkins and St. Louis Park flowed the most impaired stretch of Minnehaha Creek, with more pollution released into it per square foot than anywhere else. That was owing to land-use decisions starting in the 1930s, as businesses left Minneapolis' riverfront to resettle along freight lines.

What had been a marsh complex with a braided stream channel was filled in for streets and housing at the end of World War II. The creek became the backside of industrial corridors.

Development made the creek "flashy" or prone to rapid rising and falling. When it storms, the rain runs off hard surfaces and out of pipes, brims the creek and rushes downstream, increasing the concentration of polluted runoff.

By the time the water feeds into Lake Hiawatha, where trash, algae and dead fish accumulate, it's thick with nitrogen and phosphorus, according Minnesota Pollution Control Agency data.

The hospital fix

St. Louis Park's Methodist Hospital was built in 1959 on the north bank of Minnehaha Creek as it arches down into Meadowbrook Lake. Then the land was cheap and flood plain management in its early stages, so campus expansions over the years edged the hospital perilously close to the water.

The result was that storms would regularly cause Methodist's supply warehouses and parking lots to flood, said Duane Spiegle, HealthPartners' vice president of real estate.

More than a decade ago, hospital executives wanting to build a new addition asked the watershed district to review their plans. Conversation about a range of flooding mitigation strategies morphed into a $1.1 million partnership: the watershed district reconstructed curves in the creek to slow and filter its flow, and Park Nicollet built a boardwalk to access the restored wetland.

When the work was completed in 2009, Methodist executives cited studies showing a correlation between nature immersion, reduced pain and healing.

"When you go to the waiting room to check in for your procedure, you're looking out over this beautiful wetland that had been recreated from a kind of a drainage ditch ... [to] a meandering stream with healthy wetland plants and vegetation," Spiegle said. "Does it help in the healing process? It has to."

Methodist's wetland restoration was the first big project along the Minnehaha Creek Greenway, a 109-acre linear park along the creek that the watershed district reclaimed for public use. It became a case study in how the district can pitch to development interests the idea that restoring nature creates better habitats — for people.

The watershed district later worked with St. Louis Park to continue re-meandering the creek between Meadowbrook and Louisiana avenues, lengthening it by 1,600 feet and reconnecting it to its original floodplain. The 29-acre Minnehaha Creek Preserve was born, replete with walking trails.

Urban revival on the creek

Before the efforts of the past 15 years, not many Hopkins residents would have considered the creek an amenity, said Kersten Elverum, the city's planning and development director.

"I'm pretty confident that this whole story is really a national example of best practices," Elverum said. "And maybe because it's happened over a fairly long period of time, with lots of steps that led us to this point, the story really hasn't been shared yet."

When Hopkins officials began talking in 2008 about redesigning the Blake Road corridor, it was to break the densely populated area's reputation for crime. Many residents lived in poorly maintained duplexes, trapped along a busy road. Cottageville Park, better known for drug deals than children playing, was accessible only from an alley.

Minnehaha Creek itself was practically invisible from Blake Road, blocked by a cold storage warehouse that serviced a stream of trucks. When the warehouse site went up for sale in 2011, the watershed district stepped in and bought the site for $15 million for future development.

The watershed district then acquired and demolished an old commercial building, two small apartment complexes and a few single-family homes that stood between Cottageville Park and Blake Road. Project for Pride in Living replaced the housing with a 51-unit Oxford Village affordable apartment complex, about a block away.

That gave Hopkins the opportunity to expand Cottageville Park — creating a community garden, playground and sprawling lawn with an underground system that treats 30 acres of regional storm water and also prevents 25 pounds of phosphorus (equivalent to about 13,000 pounds of algae) from entering the creek each year.

No crime was reported at the park last year, Police Chief Brent Johnson said.

"It's a more open, family-friendly environment, and it's been pretty cool to see," he said.

Next up: Minneapolis

With Southwest light-rail construction advancing, the watershed district demolished the Hopkins cold storage warehouse and is negotiating a sale of 12 acres of the 17-acre site to luxury developer Alatus. The remaining five acres closest to the creek are reserved for a watercraft landing, trails and an overlook.

Alatus has proposed building 800 units of mixed-income housing on the site along with 17,000 square feet of commercial space, including a restaurant overlooking a storm water pond. The plans have been approved by the Hopkins City Council, and construction has begun on the first of four low- to mid-rise buildings.

The entire $300 million project, aimed for completion by 2028, will finish the Minnehaha Greenway and also serve as a regional treatment facility for 270 acres of storm water from Hopkins, St. Louis Park and Edina. The water, diverted from city pipes into the pond, will be filtered through native vegetation before being drawn through a pump system to the top of a cascade bisecting the development.

By the time the storm water discharges back to Minnehaha Creek, it will have passed through underground infiltration basins and tree trenches, making it cleaner than when it entered the site.

Now that the watershed district's 15-year project in the west metro suburbs is nearly done, officials are turning their sights to the impaired waters of downstream Minneapolis, said Michael Hayman, the district's project planning manager.

"It takes time to actually stitch together and restore these areas in a way that allows people to now enjoy them," he said. "As things start to change and areas convert from industrial corridors or rail corridors, that's been our opportunity show how we can restore the natural environment to truly live in harmony."