Waterways Restored: Case Study 6 – Powderhorn Lake in Minnesota

When the Clean Water Act is applied to American waterways, good things can happen. Our recent report, Waterways Restored: The Clean Water Act’s Impact on 15 American Rivers, Lakes and Bays, highlights waterways where the Clean Water Act’s protections and improvement provisions have had positive effects. Polluted waterways have been cleaned up, pristine waterways have been preserved, and threatened waterways have been protected. All waterways deserve these opportunities.

In this blog series, we’ll showcase individual case studies from the report. The next installment is Powderhorn Lake in Minnesota.

MINNESOTA: A Community Cleans Up Its Runoff, Taking Pride in Powderhorn Lake

Once filled with floating trash, Minneapolis’s Powderhorn Lake has been cleaned up and is now a focus of community events, including this May Day celebration in 2013. Photo: Brian Dunnette, Minnesota’s Office of the Governor

When Powderhorn Lake was first created in the 1920s as the centerpiece of a Minnesota neighborhood park, local residents enjoyed swimming in it.[i] But the construction of a nearby highway in the 1960s cut off its natural water supply. After that, nearly all the water flowing into the lake, located just south of downtown Minneapolis, was storm runoff, carrying chemicals, trash and other debris from the surrounding residential neighborhood.[ii] Today, thanks to efforts stemming from requirements of the Clean Water Act, the lake is once again a source of neighborhood pride. While its natural water supply has not been restored, and may never be, the lake’s improvements were behind the results of a 2013 newspaper poll in which Powderhorn was voted Minneapolis’s best lake.[iii]

In recent memory, Powderhorn Lake was “an extreme example of an algae-covered lake suffering from stormwater runoff in a heavily urbanized area,” according to a legislative report.[iv] By the mid-1990s, the only way fish could survive in the lake was to be stocked by state officials – even then, only the operation of mechanical aerators kept oxygen levels in the water high enough for fish to survive.[v] When an aerator broke in the winter of 1998, killing all the fish, residents of the neighborhood banded together to explore ways to restore the lake.[vi]

With the additional public attention, regulators began paying closer attention to the lake, leading to its 2002 placement on the state’s Clean Water Act-mandated list of waters impaired by pollution.[vii]

Starting in 2001, city officials boosted their efforts to clean up the stormwater flowing into the lake, as required under the terms of the city’s Clean Water Act discharge permit, including following best management practices for handling runoff.[viii] This included filtering both chemicals and large debris out of stormwater before it flowed into the Powderhorn.[ix]

The city paid to build big underground concrete basins that allow debris to settle out of the runoff, and the state-run Environment and Natural Resources Trust Fund supported a local effort to create rain gardens in lawns around the community, another best management practice to filter stormwater before it even hits the settling chambers.[x] State funding also supported efforts to reduce algae formation along the shoreline and replant native vegetation.[xi]

Thanks to that work, in 2012 the lake was removed from the state’s list of impaired waters – an important foundation point for any polluted waterway’s recovery.[xii] By then, the lake was already “one of the most popular fishing spots in the city,” according to a local newspaper report.[xiii] The following year, readers of another local paper voted Powderhorn the city’s best lake.[xiv]

Today, though not safe to swim in, and with many barriers between its current state and a return to full health, the community takes pride in Powderhorn Lake. This was evidenced by its selection in a community-wide vote as the summer 2014 home for Minne the Lake Creature, a floating public art project coordinated by the Minneapolis Parks Foundation, which is a non-profit group marshaling public attention and support for the city’s public spaces.[xv]

 

[i] Michael Kehoe, “Powderhorn Lake restoration – history,” Minneapolis Powderhorn Neighbors Forum, accessed at forums.e-democracy.org/groups/mpls-poho/messages/topic/KHS5GBhmGqEX8W5ig7Bjr, 5 September 2014.

[ii] Minnesota Pollution Control Agency, Rescuing a Treasured Urban Lake, accessed at www.pca.state.mn.us/index.php/about-mpca/mpca-news/featured-stories/resc…, 5 September 2014; Olivia LaVecchia, “Powderhorn Lake Removed From Most Polluted Waters List,” Minneapolis City Pages, 27 September 2012.

[iii] “Best Lake Minneapolis 2013 – Powderhorn Lake,” Minneapolis City Pages, 2013.

[iv] Minnesota Legislature, Clean Water Fund Performance Report, 2014, 26.

[v] Dennis Geisinger, “A Fish Story – Search Leads to Questions About Public Accountability of Park Service,” Southside Pride, May 2008.

[vi] Olivia LaVecchia, “Powderhorn Lake Removed From Most Polluted Waters List,” Minneapolis City Pages, 27 September 2012.

[vii] See note ii.

[viii] Installation date: Minneapolis Parks and Recreation Board, 2010 Water Resources Report, April 2011, 13-2;part of Clean Water Act-required stormwater treatment: Minneapolis Public Works Department, NPDES Stormwater Management Program and Annual Report, 1 June 2003, 7.

[ix] Minneapolis Parks and Recreation Board, Water Quality Projects, accessed at www.minneapolisparks.org/documents/caring/WQ_Annual_2002/2002WR_11.pdf, 5 September 2014. For more on state involvement, see also Minnesota Legislature, Clean Water Fund Performance Report, 2014, 26.

[x] MetroBlooms, Powderhorn Lake Neighborhood of Rain Gardens, accessed at www.metroblooms.org/powderhorn, 5 September 2014.

[xi] Minneapolis Parks and Recreation Board, Water Quality Projects, accessed at www.minneapolisparks.org/documents/caring/WQ_Annual_2002/2002WR_11.pdf, 5 September 2014.

[xii] Minnesota Pollution Control Agency, Rescuing a Treasured Urban Lake, accessed at www.pca.state.mn.us/index.php/about-mpca/mpca-news/featured-stories/resc…, 5 September 2014.

[xiii] Josephine Marcotty, “Powderhorn Lake Scrubs Out Pollution,” Minneapolis Star-Tribune, 26 September 2012.

[xiv] See note iii.

[xv] Minne: Janette Law, Minneapolis Parks Foundation, The People Have Spoken on Where Minne’s Floatin’, 4 June 2014; about the MPF: Minneapolis Parks Foundation, About the Foundation, accessed at mplsparksfoundation.org/about/about-the-foundation, 5 September 2014.