Benefits, costs, and feasibility of scaling up land conservation for maintaining ecosystem services in the Sebago Lake watershed, Maine, USA

Abstract

This paper integrates land use modeling, conservation planning, and ecosystem service valuation to estimate the benefits, costs, and feasibility of scaling up land conservation for maintaining natural water filtration in the Sebago Lake watershed, Maine, USA. We find that 79% of the watershed would have to be in permanent forest cover for water quality to be sufficiently maintained. However, we estimate that every dollar invested in conservation over the next 25 years will on average produce more than $10 in ecosystem service benefits, equivalent to about $90 million in net benefits per year, or $2,150/ha/yr. Additional sensitivity analysis on the discount rate, land acquisition cost, ecosystem service values, and development intensity reveals that benefits outweigh costs for more than 95% of the forested area, and 99% of high impact parcels. Furthermore, there is a business case for the top 50 water users to pay to conserve nearly 1000 hectares of forest per annum to avoid an increase in their water rates that could result if water quality deteriorated enough to require construction of a filtration plant. These findings suggest that it could be economically feasible to invest in forest conservation for much of the watershed.