Watershed Health

The primary measures of success are to establish and maintain a 100-foot or wider riparian buffer across 75 percent of the waterways and in 90 percent of the local drainage areas, and to achieve and maintain the permanent protection of 35 percent of the Long Island Sound watershed by 2035.

Status

Vegetated riparian buffers decreased in 95 percent of the subbasins in the full watershed between 1985 and 2023.  This is primarily the result of continued development in a manner that is while consistent with historical practices does not traditionally allow for greenspaces and natural areas. The most significant impaired riparian buffers occur within the coastal boundary (see Watershed Health Map above). However, between 2015 and 2023, as indicated in the Vegetated Riparian Buffer Changes map below), increases in vegetated riparian buffer were seen in 20 percent of the local drainage areas, thus some positive directional change is evident  in recent trends. Progress has been made in the development and availability of tools and imagery which enable the Partnership to better assess riparian buffer status and enable targeted action for improvement under the new CCMP.

While we currently do not have the 2025 data for the permanent protection of 35 percent of the Long Island Sound watershed, this target builds upon regional initiatives like “30 by 30,” which aim to protect 30 percent of land by 2030 while promoting ecological and community health. Protecting land in key areas such as areas adjacent to watershed streams prevents habitat loss, reduces pollution from stormwater runoff, and safeguards ecosystems that serve as natural buffers against climate impacts. The Partnership will prioritize these key areas that safeguard water quality, support biodiversity, enhance climate resilience, and provide access to green spaces for all communities.

Challenges

While this objective aims establish and maintain 100-foot or wider riparian buffers, our analysis is based on a 300-foot or wider riparian buffer, as the 100-foot resolution is currently not available. However, in the analysis, areas meeting the 75 percent vegetated buffer, of the 300-foot buffer, are confirmed to also be meeting the 100-foot buffers. On the other hand, areas with 50-75 percent may not meeting the 100-foot buffer, and less than 50 percent are considered impaired. To effectively obtain data on a watershed scale, these datasets are derived from satellite imagery. However, to assess against the 100-foot buffer, ground-truthing and/or finer resolution satellite data is necessary.

To truly address this objective, the Partnership needs to emphasize nature-based approaches. These nature-based efforts include enhancing riparian buffers, increasing urban canopy coverage, land conservation and protection, and implementing sustainable land management practices. While many of these practices have already shown promise, adopting and tracking these on a large scale is a significant effort ahead of the Partnership.

Importance

Riparian zones, the corridor or strip of land of a specified width along Long Island Sound watershed streams and waterways, with native vegetation and soils are the first line of defense against the impacts of run off from impervious surfaces such as streets and parking lots. The natural or vegetated portion of a riparian corridor is sometimes referred to as a riparian buffer.

Natural vegetated 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.

Maintaining watershed health is crucial not only for water quality, but also for mitigating flooding, supporting biodiversity, keeping land productive and ensuring food security, and enabling safe recreation. The most effective approach to ensuring a healthy watershed is to preserve and restore critical natural resources, such as riparian buffers and wetlands, while minimizing harmful practices like increasing impervious land. This holistic approach will establish a long-lasting meaningful impact for the citizens who live in and/or enjoy the Long Island Sound.