By James Walsh, Star Tribune
More than a century ago, a stream in St. Paul's Highland Park carried stormwater from higher ground over Hidden Falls. On Monday, work began to once again feed those falls with a steady flow gathered from the 122-acre former Ford manufacturing site, now known as Highland Bridge.
Through the summer, workers will build a tunnel beneath Mississippi River Boulevard that will allow runoff from a wide swath to reach the falls. This time, instead of a natural stream, a collection system resembling small ponds and a winding river will do the work.
In addition to its aesthetic and recreational benefits to what will be St. Paul's newest mixed-use development, the system now taking shape will filter pollutants year-round before returning stormwater to the Mississippi below.
Much of the system's stream path has been built and is receiving finishing touches before the water starts to flow later this month, Ryan Cos. officials said. On Monday, excavators, cranes and dump trucks moved loudly through the site.
"Ultimately, everything that comes off the site will be collected and treated before going to the river," said Nick Koch, who is overseeing construction for Ryan Cos., the site's master developer.