Watershed Assessment
Community Driven Watershed Planning and Implementation
Horsley Witten Group delivers a collaborative, data driven approach to watershed planning for state agencies and community partners. We work closely with local stakeholders to identify watershed restoration opportunities and to implement priority projects.
Our planning process emphasizes early and consistent engagement with landowners and stakeholders to gather local insight, support communication, and build community backing for implementation. Engagement tools include educational materials, online surveys, and interactive web maps. Our team has facilitated hundreds of public meetings and is committed to incorporating community input throughout plan development.
Our watershed plans include rigorous evaluation of existing water quality data, current impairment conditions, and monitoring needs to identify pollutant sources and guide restoration efforts. Assessments draw on desktop GIS analysis, review of relevant studies, hydrologic modeling, and field reconnaissance. In collaboration with stakeholders, we identify potential pollutant sources vulnerable infrastructure, and degraded habitats that can be addressed to improve overall watershed health and community access.
Project Profiles
Spofford Lake, Chesterfield, NH
HW staff collaborated with FB Environmental on a watershed-based plan to help improve water quality in Spofford Lake. Staff identified near-shore Stormwater Control Measures (SCMs) for large properties with a higher pollutant load potential. These sites included marinas, large parking lots, summer camps, clustered housing boat ramps, and roadways with poor drainage. Designers provided conceptual plans and material specifications for lakeside property owners, as well as final designs and permitting support.
Capisic Brook, Portland, ME
HW and FB Environmental led a green stormwater infrastructure assessment in a highly urbanized watershed. Staff completed a desktop analysis to identify areas of concern and opportunity; led field teams to collect data on pollution sources, stream stressors, and potential Green Stormwater Infrastructure (GSI) retrofits. The team worked with stakeholders and at technical advisory committee. HW recommended non-structural and structural practices, including potential channel-protection storage sites and GSI retrofits.
Woonasquatucket River Gateway, Providence, RI
Since 2017, HW has collaborated with the City of Providence and the Woonasquatucket River Watershed Council to transform the Woonasquatucket River area. This plan takes a holistic look at the neighborhood along the river and considers connectivity, placemaking, stormwater, and environmental improvements with extensive community engagement.
Three Bays Watershed, Barnstable, MA
HW worked with the Association to Preserve Cape Cod, the Barnstable Clean Water Coalition, and the Town of Barnstable to reduce nitrogen and bacteria loading using Green Stormwater Infrastructure. We completed extensive field assessments, identifying and prioritizing over 70 GSI retrofit opportunities throughout the watershed and have led numerous outreach activities including hands-on workshops teaching homeowners how to build rain gardens and municipal staff training addressing GSI maintenance.
Ten Mile River Restoration, Attleboro, MA
HW worked with the City of Attleboro to re-envision a former industrial stretch of the Ten Mile River. The outcome was the Riverfront Park, a passive recreational area. HW’s design included a multi-use path, kayak/canoe access, native landscaping, and park amenities. It also incorporated riverbank and buffer restoration components and invasive species management. This project is an important element of the city’s downtown urban renewal plan and greenbelt vision.
Lake Winnisquam, Belknap County, NH
HW worked with FB Environmental, the Winnisquam Watershed Network, NHDES, and US EPA Region 1 to develop a nine-element Watershed-Based Plan for Lake Winnisquam. Completed in July of 2022, the plan identifies and quantifies pollutant sources, establishes water quality goals, and outlines an action plan to help protect Lake Winnisquam.
Practice lead
Sr. Project Manager-Water Resources
Work With Us
Have a unique challenge that needs a sustainable solution?
Let's talk about what your community or organization needs and how our team of experts can help.