Stone Harbor Set to Move on Flood Mitigation Pilot Project

STONE HARBOR – Stone Harbor Director of Public Works Manny Parada Feb. 7 gave a status report to Borough Council on flood mitigation efforts.
Parada was updating council on a planned pilot project that takes a different approach to flood mitigation than the large-scale 93rd Street pump station project that was abandoned last year after projected expenses grew to over $11 million.
The pilot project involves testing the ability of three different values to successfully thwart the back flow of rising back bay waters into the borough through the drainage pipe system. The reverse flow of water is seen as a major contributor to flooding in the borough.
The pilot project will rely solely on manually operated values on three borough roadways – 93rd, 94th and 95th streets. Success with the strategy would lead to consideration of electronically controlled values throughout a larger drainage area where the borough is especially prone to flooding.
Parada described the largest potential downside to the strategy by likening the borough to a bathtub.
Once the values are closed to prevent reverse flow of bay waters, the borough becomes a bathtub that captures rainwater but has closed its drainage system, leaving the water to accumulate with no place to go. The strategy for protecting against high tide flooding produced by wind patterns and rising water levels may falter given that rising sea levels are also coinciding with stronger storms that produce major rain events.
Parada indicated in his presentation that he is not convinced that the borough will be able to avoid the expense associated with multiple pump stations for ridding the town of rainwater flooding.
One of the benefits of the pilot project, as Parada described it, is a relatively low cost for testing the strategy. Parada indicated that the pilot should be able to be implemented for no more than $220,000. He also said that part of the effort includes creating a database of photo images of flood events that will facilitate comparisons to flooding with and without the values in place.
The abandoned 93rd Street pump station project was designed to deal with a large area from 80th to 99th streets. Parada said if this value strategy is eventually adopted, the number of values would probably run to 17.
Adding to the expanded volume of values would be the cost of automating their operation, so that such a large number of points did not depend on manual intervention. No estimate was available on what a full-scale implementation of this strategy might cost.
The 93rd Street pump station strategy was in design and evaluation for several years, with the eventual dismissal of two different engineering firms. Now, the borough is attempting a new flood mitigation pilot project. Meanwhile, the timeframes are not entirely in borough control.
Sea level rise continues to occur, and intense rainstorms are becoming more frequent, independent of the speed with which municipalities implement flood defenses to protect against them. 
Thoughts? Questions? Contact the author, Vince Conti, at vconti@cmcherald.com.