Discussion on:

Can a 'sponge park' clean up one of America's dirtiest waterways?

This nice idea isn't new or unique. Stormwater retention for recharge to groundwater or for slow release to surface water (like the Gowanus Canal) has a secondary benefit by improving water quality. Stormwater basins filter out metals and organic contaminants in urban runoff and contaminants can be periodically removed by scarifying the basins during regular maintenance. There is a huge technical problem of inadequate open space to contain a large enough volume to ease the stormwater overload of a combined storm-sanitary sewer in an urban setting like New York City. Constructing sponge parks or other stormwater retention structures would require a much larger land commitment than would be feasible in densely populated cities like New York.

Good point, mikemce. The footprint of the retention scheme is prohibitive. The volume needs to be reduced by some dynamic screening/clarification process equipment that is sized for the job of stormwater runoff. Bioswales are of course good, but not enough to deal with emergencies.

If they develop a long term stratagy of building the parks as the land becomes available they can set the city up to improve in the long run.

Failing to do anything now because you think small parks are insignificant is a short sighted attitude.

It is that go big or go home mentality that has kept many cities in a down ward spiral for decades. Once the problems are over whelming they no longer have the means to deal with them, even on a small scale.

Contrary to the big government spin doctors, you do not have to spend millions or billions to fix every little problem.

another weak incomplete article - thank goodness there was a link or two to actually get any real information.
Cheers