Monday, October 15, 2012

Emnet Report on the Wet Water Pump System

We now have had several downpours at high tide to test whether the wet water pump serving the South West was making a difference in preventing flooding and water damage.

The reason why Hudson River high tide is a relevant factor, is because Hoboken has a gravity driven drainage system into the Hudson River.  Hoboken used to be an estuary with many streams running through it, many parts of Hoboken are below sea level at high tide.

Did you know that at one time, Hudson Street was part of the Hudson?  Castle Point used to be an island.  The filling in of Hudson Street is part of the long story of development in Hoboken as will all the estuaries in Hoboken.  Ever look at a title search for a Hoboken property.... many have riparian rights easements.

We have had 5 "6 month storm events" since the pumps have been installed.  Historically, once, approximately ever 6 months, we get an extreme storm typically when the Hudson River is at high tide where the rain comes down at an excessively high pace  -  an inch of rain per hour.

Pre-pump, Hoboken's low lying areas could not handle this sudden volume and these low lying areas would back up until the Hudson River tides ebbed.  It takes 8 hours for the tides to turn.  If we had a storm an hour before high tide, and 4-6 inches of rain, we would have to wait until low tide for it to START draining.  Often times, there was more than 4-6 hours worth of draining.  The tide would go up again, and we would have to wait until the next low tide for the water to continue draining.  This is how we ended up with standing water for 3-4 days after storms like Hurricane Irene which occurred right before the pump went on line (Hurricane Irene occurred in late August 2011.  The pumps went online in October of 2011).

Flooding after Hurricane Irene  -  Pre-wet water pump.  Picture courtesy of Mile Square View.

Of the 5 severe, flash flood storms at high tide, 4 did not have any un-passable standing water.  The 5th storm, it took approximately one hour for effective roads to become passable.  
This report is from November 2011.  Follow up from Emnet has been commissioned by the City Council.

 Here is the full report for your review: Emnet Report

Information Provided by Donna Antonucci
Prudential Castle Point Realty