September 2008 NJDEP Flood Update – Delaware River

The following represents a summary of some of the initiatives of the Report on Delaware River Flood Mitigation that are currently being undertaken by the NJDEP.

1. Updated Flood Hazard Area Control Act Rules
   

   On November 5, 2007, the NJ Department of Environmental Protection adopted new Flood Hazard Area Control Act rules (N.J.A.C. 7:13), which incorporate more stringent standards for development in flood hazard areas and riparian zones adjacent to surface waters throughout the State. The Department has adopted these new rules in order to better protect the public from the hazards of flooding, preserve the quality of surface waters, and protect the wildlife and vegetation that exist within and depend upon such areas for sustenance and habitat.

   In order to minimize the impacts of development on flooding, a 0% net-fill requirement (which was previously implemented only in the Highlands Preservation Area and Central Passaic Basin) will now apply to all non-tidal flood hazard areas of the State. The new rules also expand the preservation of near-stream vegetation (previously protected within 25 or 50 feet of streams) by implementing new riparian zones that are 50, 150 or 300 feet in width along each side of surface waters throughout the State. The riparian zone width depends on the environmental resources being protected, with the most protective 300-ft riparian zone applicable to waters designated as Category One and certain upstream tributaries. Certain waters supporting trout, or habitats of threatened or endangered species critically dependant on the watercourse to survive, or watercourses which flow through areas that contain acid-producing soil deposits, receive a 150-ft riparian zone.

   Some of the other highlights of the new rule include allowing the use of Federal flood mapping in communities where no State flood mapping is available, and providing a simplified method to approximate flood depths in communities where no State or Federal flood mapping is available; requiring floor elevations and roadway surfaces to be set at least one foot above the State’s flood hazard area design flood elevation in order to provide increased flood protection for buildings and public roadways; creating 46 permits-by-rule and 16 general permits to both facilitate and encourage projects that have no adverse impact on flooding and the environment, including a permit-by-rule for elevating homes, which requires no prior NJDEP approval, and a free, expedited general permit for the reconstruction and elevation of homes damaged by flooding; and Amending the Coastal Permit Program rules (N.J.A.C. 7:7) and Coastal Zone Management rules (N.J.A.C. 7:7E) to incorporate equivalent flood protection and stream buffers to all waters and flood hazard areas Statewide.

2. Updated Floodplain Study & Mapping Delineation
   
   

   The NJDEP has set aside $1,000,000 to begin the preparation of new floodplain delineations and associated mapping for the main stem of the Delaware River.  On May 16, 2006, the NJDEP executed a Collaborative Technical Partnership (CTP) agreement with the Federal Emergency Management Agency (FEMA) in order to leverage NJDEP funding with the current federal Flood Map Modernization Program resources.  FEMA will also be contributing an additional $2,500,000 dollars towards completion of this effort. 
   
   The NJDEP has also coordinated with USGS and FEMA on the development of updated hydrologic information for the main stem of the Delaware River.  On May 2007, the USGS recommended flood magnitude and frequencies for the 8 gaging stations along the main stem Delaware River in New Jersey, New York, and Pennsylvania. These figures were developed by Bob Schopp, USGS NJ Water Science Center and Gary Firda, USGS NY Water Science Center.  These figures were developed in consultation with the U.S Army Corps of Engineers Philadelphia District, FEMA Regions II and III, NJDEP-State NFIP Coordinator’s Office and DRBC.  The full USGS open-file report entitled “Flood Magnitude and Frequency of the Delaware River in New Jersey, New York, and Pennsylvania” can be downloaded at: http://pubs.er.usgs.gov/usgspubs/ofr/ofr20081203.
   
   Medina Consultants, the flood mapping contractor, is currently in the process of performing field surveys of river cross-sections along a 126 miles reach of the main stem of the Delaware River.  In addition, various stages of LiDAR acquisitions have been obtained for the four counties along the Delaware River.  The surveyed river cross-sections, the LiDAR information and the updated hydrology will be incorporated into updated hydraulic modeling for preparation of the new mapping. 
   
   All survey and LiDAR efforts are scheduled to be completed by August 2008 and the hydraulic HEC-RAS modeling will be commenced in September 2008.  Preliminary work maps are scheduled to ready by December 2008 with the official preliminary mapping to be completed and released in March 2009.
   
   This state of the art new mapping will be a valuable resource during times of emergency and for the regulation of land use along the floodplain area. The goal of this mapping effort is to more accurately define the limits of the flood hazard area and associated base flood elevation. 
   

3. Flood Mitigation Feasibility Study
   
   The NJDEP has committed funding to be cost shared with the US Army Corps of Engineers (USACE) for the preparation of a feasibility study to evaluate possible flood mitigation options, including flood-proofing and removing or relocating structures within the floodplain of the Mid-Delaware River Basin.  The Feasibility Cost Share Agreement between NJDEP and the USACE was signed on July 27, 2006.  The NJDEP and USACE have met with Delaware River town residents and local officials to perform visual inspections and gather information on the 2004, 2005 and 2006 flooding.  NJ continues to provide cost-share funding and the USACE continues to move forward on the study.

4. Upgrades to USGS Streamgaging Program
   
   The NJDEP has committed funding for the upgrade, replacement, and addition of streamgages along the Delaware River.  On June 9, 2006, the NJDEP signed a joint funding agreement with the United States Geological Survey (USGS) to provide various upgrades to streamgaging programs in NJ.  Along the Delaware River, the scope of work includes the addition of high-data rate satellite transmitters to provide better aerial data coverage on a real-time basis and to develop flood data for use in design of flood control measures, major gage repairs in order to improve streamflow data accuracy, and the addition of raingages to aid the National Weather Service (NWS) in flood-forecasting and refinement of their radar estimates of precipitation. 

   To date, major gage repairs and upgrades have been accomplished to the existing gages at the Delaware River at Montague, Riegelsville, and Trenton.  In addition, a radar stage gage has been installed and a tipping-bucket rain gage has been re-installed at the Delaware River at Stockton and a radar stage and rain gage has been installed at the Delaware River at Lambertville.

5. Multi-Jurisdictional Flood Mitigation Plan
   
   FEMA has awarded the Delaware River Basin Commission (DRBC) a grant under the Flood Mitigation Assistance program for the preparation of a multi-jurisdictional Flood Mitigation Plan (FMP) for municipalities located within Sussex, Warren, Hunterdon and Mercer Counties that have boundaries either partially or entirely within the Delaware River drainage basin.  NJDEP has provided cost share funding for the FEMA grant.  NJOEM, NJDEP, and the DRBC will lead this effort to develop the FMP, which will be part of future All-Hazard Mitigation Plans.  NJOEM, NJDEP, and DRBC have held kick-off, planning, and technical assistance meetings with county and municipal representatives in order to engage local community participation.  Local involvement in the planning process is crucial for the identification of critical facilities, flood-prone areas, community goals and desired local mitigation actions for the successful development of a FMP.  

   NJOEM, NJDEP, and DRBC worked with 43 participating local municipalities on the preparation of a draft plan which was completed and submitted to FEMA for approval in August 2008.  This plan would provide the four counties with a valuable asset that could be incorporated into a future All-Hazards Plan.

6. Updated State Hazard Mitigation Plan
   
   Representatives from a number of NJDEP programs, including the State NFIP Coordinator’s Office, actively participate in NJOEM planning and technical meetings under the State Hazard Mitigation Team.  We have implemented new processes and partnerships to address issues that FEMA raises regarding the current state plan. NJDEP participated in a core work group to support NJOEM with their FEMA required three year update, which was approved by FEMA in April 2008.   NJDEP also supports future effort that would earn the state an enhanced classification and increase the mitigation grant funding that is available for hazard mitigation projects from 7.5% to 20%.

7. Develop a Flood Analysis Modeling Tool

   The NJDEP has committed funding to the DRBC for development of a flood analysis model.  This model will allow the evaluation of existing reservoirs for flood mitigation purposes by providing data to evaluate the effects of various reservoir operating alternatives on flooding at locations downstream of the reservoirs.  The scope of work for this project has been finalized and USGS has signed an agreement with DRBC on June 20, 2007.  Development of the model will be by a multi-agency project team which will include participation of the National Weather Service (NWS), the USACE, and USGS.  The flood analysis model is scheduled to be completed within eighteen months, or in January 2009.

8. Blue Acres Program for New Jersey

   Governor Corzine signed into law the “Green Acres, Farmland, Blue Acres, and Historic Preservation Bond Act of 2007” which was presented to the voters and approved at the November 2007 election.  The bond act will provide $12,000,000 for the state to acquire, for recreation and conservation purposes, lands in the floodway of the Delaware River, Passaic River, and Raritan River, and their respective tributaries, that have been damaged by, or may be prone to incurring damage caused by storm-related flooding or that may buffer or protect lands from such damage.

last updated September 4, 2008