Millions in floodwater management programs preceded historic rainfall in southeast Wisconsin

Gov. Tony Evers this week requested a formal disaster declaration from President Donald Trump for severe flooding across southeast Wisconsin. Before historic flooding hit cities such as Milwaukee, West Allis and Wauwatosa in early August, the region’s sewerage district completed hundreds of millions of dollars’ worth of stormwater management projects decades before.

Evers’ request included Milwaukee, Washington and Ozaukee counties for the Federal Emergency Management Agency‘s Individual Assistance program, officials said. It also includes FEMA’s Public Assistance program for Door, Grant, Milwaukee, Ozaukee, Washington and Waukesha counties.

FEMA teams arrived in southeast Wisconsin last week and surveyed damage with the help of local emergency departments, and conducted a preliminary damage assessment after recent extreme storms.

FEMA found 1,500 residential structures that were destroyed or had major damage across Milwaukee, Washington and Waukesha Counties, totaling more than $33 million in damage, the governor’s office said.

“I’m grateful Wisconsin Emergency Management and FEMA’s work identified and confirmed our need for federal assistance and aid so that we can continue critical recovery efforts,” Evers said in a statement. “Now, I’m urging President Trump to do the right thing and make the appropriate presidential disaster declaration in coordination with the preliminary damage assessment—and quickly and without delay.”

Flood management work protected properties and lives

Since 1995, the Milwaukee Metropolitan Sewerage District, which manages wastewater for 29 communities, invested and built $585 million in floodwater management projects, said Bill Graffin, public information manager for MMSD. Those projects were spurred by major flooding in 1997 and 1998.

The largest visible project was on the county grounds in Wauwatosa, a 65-acre basin where Swan Boulevard cuts through. When water overflows in Underwood Creek, it spills into a structure and goes into a half-mile, underground tunnel which carries water to a 315-million-gallon basin.

“This last storm was the first time the basin has seen a significant amount of water in it,” Graffin said. “Based on photographs we’ve seen, we’re estimating around 160 million gallons captured in that basin. That kept water out of the Menomonee River, which was out of its banks in some areas.”

Another MMSD project includes a reservoir at Hart Park, which was expanded from 20 to 50 acres outside the Menomonee River, Graffin said. The park itself is designed to store floodwater until the Menomonee River has room to take it away.

In 2002, MMSD completed removal of concrete lining in Lincoln Creek in Milwaukee for $120 million. The creek drains into a 21-square-mile urban watershed, which is mostly in the city of Milwaukee. Removing concrete allowed the river to expand and protects more than 2,000 homes, officials said.

Greenseams program catches the water upstream

MMSD also operates the Greenseams program, which prevents future flooding and water pollution while supporting and protecting the district’s structural flood management projects, which are worth hundreds of millions of dollars.

By partnering with The Conversation Fund, a non-profit, the program focuses on voluntary land acquisition and storing and draining water into the ground upstream from Milwaukee’s three rivers.

“We purchase hydric soils, which are spongelike soils that absorb a lot more water than anything that’s manicured,” Graffin said. “They’re wetland soils that take thousands of years to make… We currently have five square miles of Greenseams properties, and those properties can store three billion gallons of water.”

Many of the properties MMSD are to the north, just outside of service areas, and are purchased to reduce flow into the local watersheds. The district primarily buys from private landowners, and educating potential sellers is a big part of the program. The program protects around 5,825 acres, MMSD’s website showed.

“Greenseams is a great tool for smart development and providing storage we’re going to need for excess water,” Graffin said. “Three billion gallons for $30 million is a lot cheaper than retrofitting areas with engineered, manmade flood management solutions.”

But the sewerage district still has a long way to go and a lot more concrete to remove. Currently, MMSD is looking for more places to store water at a low cost. Officials said they have more than $700 million in projects that still need to be completed, and impacts from climate change such as more intense storms and drought are still surfacing.

If a uniform inch of rain shows up on MMSD’s service area where 20 gauges measure rain across the region, it will equal out to seven billion gallons of water, according to district data. On Aug. 9 and 10, the lowest total across all rain gauges was five inches and the average was nine inches. The northwest side was hit by nearly 15 inches.