Grantee Research Project Results

Project Tasks

• Establish and maintain an effective network of scientists and agency personnel for protecting CSAs at a municipal level;
• Identify CSAs for protection by applying the variable source area (VSA) hydrology modeling techniques with local land use and natural resource condition data;
• Review the existing municipal land use plan, zoning and ordinances and developing land use plans, ordinances and BMPs that are adoptable by municipalities to protect CSAs in local communities; and
• Design and implement a set of education and outreach programs that help municipalities adopt the proposed land use plans and ordinances to protect CSAs in their communities.

Project Location

The study area includes three municipalities (Tewksbury Township, Clinton Township, and Readington Township) located in Hunterdon County, New Jersey. They have been experiencing rampant land use chances dominated by low density residential development in the past three decades. They also represent different land use development patterns with Clinton and Tewksbury as the most and least developed township among the three. The study area contains some of the most pristine streams called Category One (C1) streams that are subject to the most stringent water resource regulations based on the New Jersey Surface Water Quality Standards. Tewksbury and the north part of Clinton are also in the New Jersey Highlands Preservation Area and are subject to the intense and stringent land and water resource regulation imposed by the New Jersey Highlands Water Protection and Planning Act.

VSA Hydrology, Topographic Index and Critical Source Areas

The VSA hydrology applies a saturation-excess hydrological process to explain how runoff is generated primarily from discrete saturated areas in the landscape. VSAs are these saturated areas that actively contribute to generating runoff. The term VSA implies the extent of saturated runoff source areas varies with soil moisture state. Given certain natural resource conditions in an area, VSAs would develop and expand and shrink in a similar pattern for each storm event. The topographic index is used to derive VSA patterns in landscape that simulates the pattern of surface runoff contributing areas following the VSA hydrology.

Since VSAs are the portions of a landscape that actively contribute to generating runoff, the parts of VSAs that most actively contribute to runoff generation are defined as hydrologically sensitive areas (HSAs). CSAs are determined as the intersection of the HSAs and a set of pollutant source areas in landscapes. The pollutant source areas generally refer to the areas in landscapes that have been actively generating pollutants because of intensive land use activities such as agricultural and silvicultural production, residential development, and industrial and commercial uses.

Community Engagement Planning Process

An interactive three-tier Community Engagement Planning Process is adopted to engage municipalities and their associated regulatory and professional supporting communities through sharing project results, conducting small interest group meetings, roundtable discussions and presentations and providing feedbacks and follow-up to:

• Educate municipal officials and Professional Planners on science behind Critical Source Area model
• Integrate scientific model results and mapping outputs for each municipality based on their water resource planning framework
• Obtain feedback on reality of incorporating modeling results into township planning documents
• Gain acceptance of the recommended land use plans, ordinances, and BMPs that protect CSAs in the targeted municipalities and beyond

Municipal Review and Land Use Controls

Various land use control measures such as municipal land use plan, ordinances and regulations as well as federal and state programs on smart growth, water pollution, stormwater management, open space and farmland preservation are implemented at a municipal level to direct local land use decisions and protect land and water resources. These land use controls were reviewed for each of the three municipalities to determine at what extent the identified HSAs and CSAs are being protected from intensive land uses in the future by those controls and to evaluate the opportunity of protect the HSAs and CSAs. The land use controls being reviewed include:

• Stream corridor protection mandated by New Jersey Department of Environmental Protection (NJDEP) Stormwater Management Rule (NJAC 7:8), NJDEP Flood Hazard Control Act (NJAC 7:13); wetland protection and mitigation, and municipal stream buffer ordinances.
• State, county, municipal and private preserved open space and farmland;
• Municipal steep slope ordinances that restrict certain developments on the areas with steep slope; and
• More stringent requirements on stream corridor protection and steep slope restrictions in the New Jersey Highlands portion of the study area imposed by the New Jersey Highlands Water Protection and Planning Act.

 

 

Field Soil Moisture Measurement

Three fields with distinct land use types in Tewksbury Township were selected to measure soil moisture to evaluate the VSA pattern predicted by the topographic index. Three fields include a natural preserved area, a passively managed recreational park and an active farm with intensive cropping activities. A time domain reflectometry (TDR) Soil Moisture Meter was used to sample soil moisture and a Global Positioning System (GPS) to record the precise location of the sampling points. All three fields have been visited two times, once just after a rainfall event and once during a dry time period. The measured soil moisture data were being analyzed to determine whether the topographic index predicted the actual soil moisture patterns spatially and statistically.