The city of Minneapolis and the 1800 Lake apartment developer couldn’t reach a settlement this fall, and litigation continues over millions of gallons of diverted groundwater pumping into the lakes.

The apartment building’s lowest parking level sits below the water table at Lake Street & Knox Avenue, and dewatering pumps are discharging water into a storm drain that flows into the channel between Lake of the Isles and Lake Calhoun. If pumping stopped for more than an hour, the garage would flood, according to city staff. The rate of water discharge is 170 gallons per minute, or more than 89 million gallons per year.

The city has filed a motion for summary judgment, asking the developer to permanently stop pumping water into the storm sewer and pay damages to the city. The developer in turn has filed complaints against its architect and engineers, saying they didn’t adequately account for the proximity to the lake.

A Dec. 29 trial date is on the Hennepin County District Court calendar.

Lake Calhoun’s water clarity has decreased since pumping began in 2011, according to an August report by Jeff Lee, a Barr Engineering aquatic ecologist retained by the city of Minneapolis and the Park Board. He draws a connection between the discharge and an 8 percent increase in phosphorous in Lake Calhoun. He said one pound of additional phosphorous can lead to growth of 500 pounds of algae in a lake, and in this case, 1800 Lake is adding 75.6 pounds of phosphorous to Lake Calhoun each year.

Attorneys for Lake and Knox LLC say the Minnesota Pollution Control Agency evaluated the groundwater discharge in 2011, and didn’t have concerns with the water quality.

Could it happen again?


Nearby developers are hoping to avoid the same problems by building above the water table.

The city approved three new apartment projects this summer near Lake Calhoun: A six-story building where Tryg’s is today at 3118 W. Lake with underground parking above the water table; an eight-story project next to Calhoun Beach Club at 2622 W. Lake standing three feet above the water table; and a three-story apartment building with no basement at Lake & James (proposed by CPM developers who also worked on 1800 Lake). CPM is also proposing apartments reaching four-six stories at Lagoon & Irving, projected to stand four feet above the water table.

Lee said building above the water table is one option to prevent a problem with groundwater, and said there are many other strategies, such as waterproof basements. He noted that the water table fluctuates based on precipitation.

CPM co-founder Dan Oberpriller told East Isles residents in September they don’t need to worry about a repeat of 1800 Lake’s water issues. He said the city’s dewatering application process now requires the input of hydrologists and soil engineers and a study of water table fluctuations.

“The city will definitely not allow anything else to happen,” he said.

As for overall review of new development projects, the city’s requirements have not changed, according to Lisa Cerney, Minneapolis director of Surface Water and Sewers. But staff are asking for more detailed information from developers to complete their review, she said.

Building near the water


The height of new development near the lakes has been the subject of extensive neighborhood debate.

All of the aforementioned projects stand inside the city’s Shoreland Overlay District, which requires a conditional use permit to build above 2.5 stories within 1,000 feet of the water.
The Park Board has gone on record opposing development at the fringe of parkland that exceeds the Shoreland height limits, saying the district “seems to be routinely ignored these days in these most cherished and fragile natural areas of our city.” The Park Board recently recommended a “performance-based” review that takes the public benefit of a project into account, and praised the 2622 W. Lake developer’s receptiveness to new trail linkages.

Current and former staff from the Department of Natural Resources said height rules in the statewide Shoreland district standards were created to deal primarily with aesthetic issues, rather than environmental concerns.

Minnesota DNR scientist Paul Radomski tried to update state Shoreland rules in 2009. He explained that the DNR originally proposed the 2.5-story limit to respect the tree line and soften the visibility of new structures. But Minneapolis officials have the authority to decide the type of aesthetic they want around the lakes, he said. The proposed revision of statewide Shoreland standards would have actually provided greater flexibility on height rules, though they were blocked by then-Gov. Tim Pawlenty.

Radomski said the larger environmental issue for lakefront development relates to stormwater management, rather than building height.

“When you look at the number of culverts that flow into Calhoun … you can see the sediment that’s coming off the neighborhood,” he said. “That’s a larger, more serious concern that all cities in Minnesota have to address.”

As for a long-term solution at 1800 Lake, a city consultant has suggested creating a barrier to prevent water from entering the basement.

A report by Anchor QEA, commissioned by the defense attorneys, offered more ideas to fix the problem. They suggested creating a deep well injection to send water into the aquifer, or reducing the rate of water flow below the basement. Water could be treated before discharge and chilled in winter. (The warm water discharge has prevented ice from forming in the lagoon.)

The discharge could flow through the storm drain, route to a sanitary sewer system at Irving & The Mall, or settle on Park Board land at open space located north of the lagoon and south of Lake of the Isles Parkway.

Anchor QEA did not investigate the possibility of terminating pumping and flooding the basement. An analysis by EB Herman Companies conducted on behalf of the developer said the property would lose $7.85 million in value if the lower level of the parking garage was no longer functional.

The city is aiming to stop the discharge altogether.

“They have to stop pumping groundwater,” said City Attorney Susan Segal.