Across the Nashua River watershed, healthy streamflow is being impacted by stream crossings (culverts, bridges, fords) that are undersized, improperly designed, or that have been damaged by erosion and settling. Perched stream crossings can disrupt stream continuity and negatively impact movement of aquatic species, when, for example, erosion leaves a culvert sitting above the level of the stream. Poorly designed crossings can also alter natural water flow patterns, impacting the ecological processes that depend on consistent streamflow, such as fish spawning and migration. Undersized culverts and bridges can lead to road/property damage and flooding during heavy storm events, an increasing issue with climate change.
To effectively address these challenges, the first step is to assess which culverts require attention. Following this, communities can prioritize these culverts for redesign and upgrade to improve stream connectivity and climate resiliency. The North Atlantic Aquatic Connectivity Collaborative (NAACC), a network of individuals from universities, conservation organizations, and state and federal natural resource and transportation departments focused on improving aquatic connectivity across a thirteen-state region, has developed a comprehensive protocol for assessing culverts, established a database for recording and sharing assessment data, and implemented a training and certification program for individuals interested in conducting these assessments.
With project funding from the NSN Rivers Wild & Scenic Stewardship Council, Nashua River Watershed Association (NRWA) staff member Utkir Adkhamov, who is a certified Level 1 Coordinator by NAACC, trained other NRWA staff, state agency employees, conservation colleagues and community volunteers in NAACC protocols which made them eligible for certification. These certified individuals are now qualified to conduct assessments of priority stream crossings throughout the MA portion of the watershed.
Additionally, the Stewardship Council funded NRWA staff field training by the New Hampshire Stream Crossing Initiative to integrate their data collection into the Statewide Asset Data Exchange System (SADES), which is the protocol for NH assessments. Once trained, NRWA staff mapped, prioritized, and assessed crossings in the NH portion of the Nissitissit subwatershed.
With the momentum built by the Stewardship Council funded projects, the NRWA applied for grant from the MA Division of Ecological Restoration through the Stream Continuity Program, which allowed NRWA staff to assess over 500 additional stream crossings in Fitchburg, Lancaster, Leominster, Rutland, and Sterling.
This project supports the NSN Stewardship Plan in a number of goals related to protecting, enhancing, and restoring aquatic habitat and stream continuity, specifically in the Biological Diversity Action Plan, Goal A4 Protect and Enhance Coldwater Fisheries Resources, Improve culverts and crossings; Goal A5 Protect and Enhance Anadromous Fisheries, Provide stream crossings; Goal A6 Sustain and Improve Populations for Freshwater Mussels, Improve stream connectivity; and Goal C1 Maintain and Enhance High-quality Riparian Habitat, Objective Minimize loss of valued habitat, with multiple bullet points related to proper culvert design and installation.