The following article by Ben Johnson was published in the June 5, 2014 issue of the Southwest Journal:
Park Board warns it won’t sign off on SWLRT tunnel without further study
Last week the Park Board passed a resolution that warned it won’t approve a shallow tunnel underneath the Kenilworth Channel for the Southwest Light Rail (SWLRT) line without further study.
The Park Board’s power to influence SWLRT comes from Section 4(f) of the Federal Transportation Act: http://www.ecfr.gov/cgi-bin/text-idx?SID=7ab7224094967f634c431b7a10cfb0fc&node=23:188.8.131.52.46&rgn=div5 . It states that federal transportation funds may not be dispersed for any project that affects parks or historic sites unless there is “no feasible and prudent avoidance alternative” for use of the land or property.
Previously the Park Board passed resolutions declaring that a deep tunnel or freight relocation were the only acceptable options at the Kenilworth Channel. Now with both of those options appearing unlikely, commissioners want to make absolutely sure that the shallow tunnel can be done without harming the Chain of Lakes.
Park Board Assistant Superintendent Bruce Chamberlain said that Barr Engineering has identified a number of potential issues that need to addressed before moving forward with a plan that includes a shallow tunnel. Those issues include concerns about ventilation, water infiltration and the long-term stability of the tunnel.
“How will the buoyancy effect what be counteracted?” asked Chamberlain. “This would be below the water table, so how to we keep this tunnel from popping out of the ground?”
A hydrological study has already been performed at the request of the Park Board, and it found that the tunnel shouldn’t impact the groundwater in a significant way, according to Chamberlain. Still, commissioners are skeptical of any plan that allows light rail trains to be routed through the skinny channel connecting Cedar Lake and Lake of the Isles.
“I’m opposed to this coming through the channel at all,” said Commissioner Annie Young. “I have a distinct feeling we’re not going to be able to stop this project, it’s going to happen and we’re not going to be able to do a damn thing about it.”