CONTACT: Michael Globetti, DNREC Public Affairs, 302-739-9902
DNREC proposes revising floodplain hazards for South
Branch Naaman Creek in New Castle County communities
DOVER (Dec. 8, 2015) – DNREC’s Division of Watershed Stewardship has performed a floodplain study and submitted a Letter of Map Revision (LOMR) request to FEMA for revising the floodplain for the tributary of South Branch Naaman Creek, generally located in Brandywood and adjacent New Castle County communities. DNREC will issue a public notice for flood hazard revisions Wednesday, with the revisions expected to be effective in May 2016. These maps are used to enforce floodplain construction codes, and relied on by lenders to determine flood insurance requirements.
The effective tributary floodplain is currently mapped Zone A, which appears to have its origin in “USGS Floodprone Quad Maps” from 1971, and does not appear to be based on modern modeling techniques or accurate topography. The South Branch tributary flows through the backyards of a built-out subdivision and has an entire watershed area of only one-half square mile. “Known map inaccuracies led a number of residents to successfully petition FEMA for Letters of Map Amendment (LOMA), which corrects the map error and removes their houses from the regulatory floodplain,” said Janice Shute, project engineer, DNREC Division of Watershed Stewardship.
DNREC performed updated hydrology and hydraulics studies utilizing current rainfall, topography information and modeling techniques. The tributary will now be mapped Zone AE, which provides more detailed information about flood levels. Most of the homes currently in a mapped floodplain will be removed from the floodplain with this revision. However, Ms. Shute said, the analysis does not anticipate future land development or changes in rainfall patterns, so landowners living near a floodplain may want to consider purchasing floodplain insurance for their protection.
DNREC’s mapping priorities are to replace aging floodplain studies and poorly mapped floodplains with an appropriate level of study. In addition, outreach and communication tools are being developed to better communicate risk to local residents and communities. Currently, DNREC has countywide studies underway in all three counties on approximately 335 stream miles. Revised county maps are anticipated to become preliminary in March 2016. The adoption process for the maps to be accepted by FEMA and become effective may take 12-16 months from the preliminary date.
For more information, please contact Janice Shute, project engineer, DNREC Division of Watershed Stewardship, at 302-739-9921.
Vol. 45, No. 419