EXAMINING THE EFFECTS OF URBANIZATION AND CLIMATE ON A SMALL NEW ENGLAND COASTAL WATERSHED

The West River and its tributaries flow through Bethany, Hamden, Woodbridge, West Haven, and New Haven townships of southwestern Connecticut before reaching the New Haven Harbor and the greater Long Island Sound along the state’s shoreline. The watershed area of the West River is about 90 square kilometers and the river, and the tributaries together comprise of nearly 100 kilometers of stream channels. The southeastern portion of the watershed, which is the focus of this study, is heavily urbanized with large swaths of impervious surfaces. To understand the extent to which this urbanization impacts the health of the West River and its tributaries, stream stage, stream temperature, and water quality (Dissolved Oxygen, pH, Conductivity etc.,) were continuously monitored at seven different stream locations over a period of three months from late September to December 2021. Stage and stream temperature measured at 10-minute intervals when compared with local weather data, land-use, slope, and other watershed attributes showed discernible patterns of influence of urbanization in different areas with varying degrees of urban land-uses ranging from 9- 87%. Water quality data that was collected less frequently showed no significant changes; likely given the short duration of monitoring in a cooler and wetter New England fall climate. Broadly, our findings also highlight the need for longer term, high frequency data for a more complete understanding of the ways in which urbanization affect small coastal watersheds of the region, and how studies like ours may also help reveal how old coastal cities like New Haven with less than adequate stormwater management infrastructure may fare in the face of more intense and chaotic weather patterns in the region.