It seems clear that political officials who favor a pair of “shallow tunnels” between Cedar Lake and Isles for the Southwest Light Rail Train are not educated about the threat of reduced recharge to Cedar Lake. Reduced recharge means reduced water quality. I have repeatedly asked at Hennepin County Commission SW LRT meetings for an estimate of the dewatering amount for the proposed construction project and never had my inquiry acknowledged or answered.
Cedar Lake originally emptied to the northeast, into Bassett Creek. During the early 1900s rowboat craze, the Kenilworth Lagoon was dug between Cedar Lake and Isles, reversing the Cedar drainage from Bassett Creek to Minnehaha Creek along the Chain of Lakes.
In the mid-1990s, the Seattle-based landscape architects Jones & Jones working on the design for the north part of the Cedar Lake Trail dug and dug but could not find the old northeast outflow path from Cedar Lake. Water channels and springs can be disappeared.
If the SW LRT double tunnel plan is adopted almost 9/10s of a mile (4700 linear feet) on the south and east of Cedar Lake will cut off a huge percentage of recharge groundwater feeding into the lake. Cedar Lake is spring fed. I live in Bryn Mawr, Cedar is my swimming lake. I feel the cool spring water here and there when I swim across Cedar in the summer.
Several years ago I asked former County Commissioner Gail Dorfman about the water vis-à-vis SW LRT and she said the water had not been considered. That, of course, was before any tunnel plans. Lots of numbers are quoted about the proposed SW LRT but no one is talking numbers about the water, specifically the amounts and path of dewatering and the threat to recharging Cedar Lake. Where are the water studies?
The Great Medicine Spring and Glenwood Spring
The Great Medicine Spring in Theodore Wirth Park along with nearby Glenwood Spring were permanently dewatered into the sewer system in the late 1980s with Interstate-394 construction. The practice was to dynamite and dewater both sides of a roadway. Dewatering, like tiling a wet field for agriculture, uses buried pipes with holes where groundwater drips in and is channeled away.
The I-394 dewatering system, designed by MnDOT, funnels 2.5 million gallons of water a day into downtown sewers and mixes with street runoff during storms. Where the Bassett Creek pipe vomits water into the Mississippi a sign reads: WARNING Pregnant women and children under 6 should not eat fish taken here.
Roads and water don’t mix. City water is now piped into the Wirth Park tamarack bog.
“In 1874, Col. John H. Stevens, the first settler in Minneapolis, said that this [Great Medicine] spring was frequented by Native Americans, ‘who came hundreds of miles to get the benefit of its medicinal qualities.'” (Greg Brick, MN Ground Water Association, Vol. 16, No. 1, March 1997, p.6.)
Whatever unique properties the Great Medicine Spring contained are lost forever. Calcium and magnesium would have been in the water that trickled through limestone cracks, but what else? Imagine patients walking “hundreds of miles” for this curing water, this immune booster-plus liquid that restored the body. The Medicine Spring was unlike any other spring in our spring-rich landscape.
“Our most famous surficial spring is Glenwood-Inglewood Springs, known at office coolers throughout the Metro area. Winchell (1905) drafted a cross-section of the geology of this spring, showing how the water emerged from a gravel-clay contact on the banks of Bassett Creek, in Minneapolis. The water utilized at present is not derived from the original spring but from pipes driven through the clay into a water-bearing sand bed. Other surficial springs feed the Minneapolis chain of lakes. (Brick, Ibid.)
It is difficult to visualize underground water veins because they are invisible to us. Looking at other development projects in Minneapolis can reify the threats.
Lost Minneapolis Lakes
Minneapolis lost the quality of Brownie Lake to the Brownie-Cedar channel built in 1917 when Brownie dropped 10 feet. Another five foot drop occurred with the Kenilworth Canal between Cedar and Lake of the Isles. Brownie, in a hole protected from the winds, no longer “turns over” at springtime refreshing the lake’s oxygen so that layers of the lake do not support life.
Loring Lake “fed by unfailing springs of pure water” began to fail as early as 1887 with surrounding development.
Tiny Spring Lake at the base of Lowry Hill was acquired in 1893 but is now hidden by I-394. Brownie and Spring lakes function as views for people to walk around.
Powderhorn Lake began being reshaped, dredged and deepened but reduced in size, in 1895. By 1899 storm water intrusion affected water quality. Water level drop in Powderhorn was reported in 1911 and 1921. The lowest lake level was related to the 1963 trench dug for I-35W.
Development has huge support among politicians especially in an election year. But who is representing the water?
“Nature does not negotiate,” Kumi Naidoo, executive director of Greenpeace International reminds us. We are some of the 15 million Americans who flush our waste water and drink out of the Mississippi. Our bodies are 70 percent water.
Lengthy shallow tunnels for a fixed SW commuter train that hardly serves city residents is proposed for the sieve that is the lake-blessed city of Minneapolis. It is a near sighted, flawed plan.