U.S. Department of Agriculture: Forest Service -- National Agroforestry Center


Date of this Version



Diversity and Distributions, (Diversity Distrib.) (2013) 19, pp. 1198–1207, DOI: 10.1111/ddi.12103.


U.S. government work.


Aim Biodiversity and drinking water share a common interest in land conservation. Our objective was to identify where that common interest occurs geographically to inform conservation planning.

Location The study focused on 2112 eight-digit hydrologic units (watersheds) occurring in the conterminous United States.

Methods Data on aquatic-dependent species occurrence, drinking water intakes, protected land status and land cover change were compiled for each watershed. We compared these four datasets after defining ‘hotspots’ based on attribute-specific thresholds that included (1) the 90th percentile of at-risk aquatic biodiversity, (2) with and without drinking water intakes, (3) above and below the median percentage of protected land and (4) increase in urban land above and below a 1% threshold between 2001 and 2006. Geographic intersections were used to address a number of questions relevant to conservation planning including the following: What watersheds important to aquatic biodiversity are also important to drinking water? Which watersheds with a shared stake in biodiversity and drinking water protection have inadequate land protection? Which watersheds with potentially inadequate amounts of protected lands are also undergoing relatively rapid urbanization?

Results Over 60% of the watersheds that were determined to be aquatic biodiversity hotspots also had drinking water intakes, and approximately 50% of these watersheds had less than the United States median amount of protected land. A total of seven watersheds were found to have shared aquatic biodiversity/ drinking water values, relatively low proportions of protected lands and a relatively high rate of urbanization. The majority of these watershed occurred in the south-eastern United States, with secondary occurrences in California.

Main conclusions Geographic analysis of multiple ecosystem services can identify areas of shared land conservation interest. Locations where ecosystem commodities and species conservation overlap has the potential to increase stakeholder buy-in and leverage scarce resources to conserve land that, in this case study, protects both biodiversity and drinking water.