Nokomis Groundwater Update & Public Meeting on 10/24


October 9, 2018

Project team looking at groundwater issues in Nokomis area

For the past several years, residents in the Nokomis area of Minneapolis have expressed concerns over rising groundwater levels and higher water levels in Lake Nokomis.  Their concerns include impacts to sewer infrastructure and standing water in previously dry areas near Solomon and Nokomis Parks.

To respond to these concerns, the city of Minneapolis launched a partnership with the Minneapolis Park and Recreation Board, the Minnehaha Creek Watershed District, Hennepin County and the Minnesota Department of Natural Resources. The group has committed significant resources, including the time and expertise of more than 30 staff, toward better understanding what’s going on with groundwater and surface water levels in the area, how they may be interacting, what might be done to address problems, and how to keep stakeholders informed. Actions taken to date include:

  • Four observation wells have been installed at Solomon Park and Nokomis Park to provide better information about groundwater levels and movement in the area.
  • Two deeper bedrock aquifer wells will be installed in the near future.  The six wells together will provide additional information about groundwater levels and movement in the area, including vertical movement of groundwater.
  • An inter-agency technical team consisting of hydrologists, geologists, planners, ecologists and engineers has met four times to analyze existing data and identify needs for further information.
  • Lake Nokomis water level data have been analyzed in relation to what is known about the soils and geology in the area, as well as in relation to the location of residential reports of groundwater issues with sewer laterals or foundations.
  • A project website has been set up, and an inter-agency team has been established to coordinate communications and outreach to the public.
  • A preliminary overview of some of the drivers of higher water levels has been gathered into a fact sheet that is available on the project website.

Late summer drought followed by rainy fall

The biggest factor affecting water levels in and around Lake Nokomis is something everyone loves to talk about, but no one knows how to fix: the weather.

During most of this past August, for instance, the Twin Cities metro area was listed as “Abnormally Dry” on the U.S. Drought Monitor. That dry weather resulted in lower water levels in Minnehaha Creek and on Lake Nokomis for several weeks. The lack of rain left Minnehaha Creek running on the low side from July 26 through September 19. The water level on Lake Nokomis also dropped below the weir’s outlet elevation of 815.10 feet sometime around August 11, meaning water could no longer flow from Lake Nokomis to Minnehaha Creek. It remained below the outlet through mid-September. Prior to 2018, the last time the water level on Lake Nokomis dropped below the outlet elevation was on November 28, 2017.

In 2018, due to dry weather, water flowed out of the lake via the weir for only 53 days. In comparison, from mid-March to the end of December 2017, the weir was open for 121 days and water flowed out of the lake until it dropped below the outlet elevation at the end of November.

Recent rainfall has prompted the reopening of the Lake Nokomis weir. On September 25 the lake level measured 815.98 and water is once again flowing out of the lake.

The weir is a dam-like structure that prevents polluted stormwater and zebra mussels from entering Lake Nokomis from Minnehaha Creek. The Minneapolis Park and Recreation Board operates the weir in coordination with the Minnehaha Creek Watershed District consistent with an approved operating plan. For more information, view the Lake Nokomis Outlet Operating Plan.

City completes sewer pipe replacement at Solomon Park

After video images showed significant deterioration in the 60-year-old concrete sanitary sewer pipe running along 14th Avenue in Solomon Park, the city of Minneapolis hired a contractor this summer to replace it. To minimize damage to trees in the park, the contractor used a minimally invasive technique called “pipe bursting,” which uses a tool to break up the old pipe underground while pulling new plastic pipe through behind it. During construction, which ran from mid-August to mid-September, crews observed a minimal amount of groundwater seeping into the three pipe-bursting pits. That groundwater was pumped directly into the sanitary sewer.  The new high-density plastic pipe running from 58th Street to 59th Street is now in place and fully functional.  

Open house to be held later this fall

Nokomis Groundwater Open House meeting details

As part of efforts to keep area residents informed and engaged, the Nokomis Area Groundwater and Surface Water Evaluation team is planning an open house on Wednesday, Oct. 24, from 6 to 8 p.m. at the Lynnhurst Recreation Center, 1345 W. Minnehaha Pkwy, Minneapolis.

No formal presentations are planned, but staff from the City of Minneapolis, the Minneapolis Parks and Recreation Board, the Minnehaha Creek Watershed District, the Department of Natural Resources and Hennepin County will be on hand to provide information and answer questions on a variety of topics related to groundwater and surface water issues in the area. 

Future Nokomis Area Groundwater & Surface Water Evaluation Project Updates

To continue to receive updates on this issue, please sign up to receive email updates on the Nokomis Area Groundwater & Surface Water Evaluation Project. You can also visit the project website to learn more.

For reasonable accommodations or alternative formats please call 311 at 612-673-3000.

People who are deaf or hard of hearing can use a relay service to call 311 at 612-673-3000. TTY users can call 612-673-2157 or 612-673-2626.

Para asistencia 612-673-2700, Yog xav tau kev pab, hu 612-673-2800, Hadii aad Caawimaad u baahantahay 612-673-3500.