Twelve years ago, Baltimore spent $2.2 million on an erosion control project in a stream called the Stony Run that flows through a beautiful wooded park in North Baltimore. The city brought in bulldozers, cut down about 150 trees, and built rock walls and dams in an effort to slow the water’s flow.
The project succeeded in creating a series of pools in which minnows now live. But there is no evidence that it achieved its main objective: catching and reducing sediment, nitrogen, and phosphorus pollution being washed downstream into the Chesapeake Bay.
Then, about two years after it was built, rain storms overwhelmed the system. The storms knocked the streamside boulders down into the waterway and required the construction crews and backhoes to return to the park again to fix it, temporarily.
A few years later, this fix was undone by another set of rain storms that again bashed the rocks out of place -- requiring a new round of repairs, this time costing $500,000.