Co-designed land-use scenarios and their implications for storm runoff and streamflow in New England

Future changes in both landscape and climate have the potential to create or exacerbate problems with stormwater management, high flows, and flooding. In New England, four plausible land-use scenarios were co-developed with stakeholders to give insight to the effects on ecosystem services of different trajectories of socio-economic connectedness and natural resource innovation. To assess the effects of these land-use scenarios on water-related ecosystem services, we applied the Soil and Water Assessment Tool to two watersheds under two climates. Differences in land use had minimal effects on the overall water balance but did affect high flows and the relative contribution of storm runoff to streamflow. For most of the scenarios, the effect was small and less than the effect due to climate change. For one scenario – envisioned to have global socio-economic connectedness and low levels of natural-resource innovation – the effects of land-use changes were comparable to the effects due to climate. For that scenario, changes to the landscape increased the annual maximum daily flow by 10%, similar to the 5-15% increase attributable to climate change. These results, which were consistent across both watersheds, can help inform planning and policies regarding land use, development, and maintenance of hydrologic ecosystem services. Research highlights Stakeholder-engaged scenarios provide meaningful and plausible futures for the New England landscape and assessment of effects of land-use change on storm runoff and streamflow Effects of land use on the overall water balance are small across the landscape scenarios Future land-use change has the potential to affect storm runoff and high flows to a degree that is comparable to the effects due to changes in climate in 2060 The degree of natural resource innovation affects storm runoff and high flows when population growth is large and has a negligible effect when population growth is low