Photos of the Long Island Sound

Research & Monitoring

Status & Trends

LISS Ecosystem Targets and Supporting Indicators

Riparian Buffer Extent

Increase the percent area of natural vegetation within 300 feet of any stream or lake in the Connecticut and New York portions of the Long Island Sound watershed to 75% (1,030 square miles of natural vegetation) by 2035 from 2010 baseline of 65%.

% of natural vegetation (riparian buffer) in 300-foot river corridors by sub-basin
( Click labels in legend to hide data and adjust scale )
Progress

 

Total Area of Vegetation Along 300-foot Riparian Corridor (sq miles)
NY (vegetated)CT (vegetated)Total NY/CT (vegetated)Total NY/CT (vegetated/ developed)% NY/CT (vegetated)
198530.47895.57926.041374.0267.40
199030.20881.07911.271374.0266.32
199529.75870.19899.941374.0265.50
200229.51863.64893.161374.0265.00
200629.46860.45889.911374.0264.77
201029.31858.59887.901374.0264.62
201529.28860.59889.861374.0264.76
Percent to Goal
YearTotal Vegetated Area (sq. mi)Net Total from Baseline (sq. mi.)% Vegetated (rounded to nearest whole number)By 2035, Increase Vegetated Buffer by 10% to 1,030 sq. mi. from Baseline
2010887.90065%-
2015889.861.9665%0

Status and Trends

Meeting this target requires an average increase of vegetated riparian buffers of 0.4% per year from 2010-2035. A 30-year dataset up to the baseline year of 2015 indicates that vegetated buffers in riparian zones are declining, but the largest declines occurred between 1985 and 2002.  From 2010, the baseline year for the CCMP ecosystem target, to 2015, there was a slight increase of 1.96 square miles of vegetated area (from 887.9 to 889.86 square miles or 64.62% vegetated to 64.76% vegetated. The increase reflects an average increase of .22% over the five year period or about .05%  a year, which falls short of what is needed to achieve the ecoystem target of reaching 1,030.5 square miles of vegetated area by 2035. If the percentage is rounded to the nearest whole number than both years would be at 65%, and there would be no change from the baseline.

There are a total of 1,314 square miles of riparian corridor in Connecticut and 60 square miles in New York within 300-foot riparian corridors in the  the Long Island Sound watershed.The total includes developed area, which increased by 32 square miles from 1985 to 2015.

Challenges

Limit development and/or build development with green infrastructure around the shorelines of all water bodies in order to provide a buffer that effectively removes groundwater before it enters into receiving waters.

How is This Target Measured?

University of Connecticut Center for Land Use Education and Research (CLEAR) has tracked riparian buffers within 300-feet of streams and waterways  about every five years  in the Long Island Sound watershed  using satellite imagery  (See Data Note).

Importance

Riparian zones, a corridor or strip of land of a specified width along streams and waterways, with native vegetation and soils are the first line of defense against the impacts of impervious surfaces such as streets and parking lots.

Natural riparian areas slow runoff, protect shorelines from erosion, aid in flood control, and filter or trap pollutants. They also provide habitat and corridors for wildlife, as well as shade waters for fisheries enhancement. Additionally, intact riparian corridors may provide scenic value and recreational opportunities.

The natural or vegetated portion of riparian corridors are sometimes referred to as riparian buffers.

Additional Information

There are very few subwatersheds in Long Island Sound with sufficient riparian buffers to assure “pristine” water quality of streams and rivers.

The higher the percentage of naturally vegetated land in this buffer zone is, the healthier the stream or river will be. A rough rule of thumb is that a river with >90 percent  of the buffer zone vegetated is considered “pristine”, while a river with <75 percent vegetated buffer is considered “impacted.” The above map showing the health of riparian buffers by subbasin reveals that there are few subbasins with the vegetated cover necessary to be considered pristine.

Contact

Robert Burg, New England Interstate Water Pollution Control Commission
[email protected]

Source of Data

UConn Center for Land Use and Education Research

Data Notes

  • The technical explanation on how the target was selected is found in Appendix B of the Comprehensive Conservation and Management Plan.
  • The methodology used to map the riparian zones is described at the UConn CLEAR website.

 

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