Kroll, S.A., R.J. Horwitz, D.H. Keller, B.W. Sweeney, J.K. Jackson, and L.B. Perez. 2019. Freshwater Science 1:23–29.
Watershed restoration for mitigating or preventing impacts of human land use on aquatic ecosystems is now big business and is far more common and consumes far more financial resources than 10 to 20 years ago. The effects of restoration are assumed to be improvements in stream ecosystem integrity. However, there is not conclusive evidence that shows that most watershed restoration and mitigation projects produce expected environmental and biological changes. Here we present and discuss 4 major challenges associated with the planning, execution, and monitoring of large-scale restoration programs aimed at improving the ecosystem integrity of streams (and their downstream rivers and estuaries), with a focus on agricultural best management practices and urban stormwater control measures. These challenges are 1) the lack of holistic planning for implementing and monitoring large-scale restoration projects, 2) planning that does not include geographic context or considerations of scale, 3) a failure to tie monitoring to specific goals and predicted improvements in ecosystems, and 4) the limited and parochial approach to monitoring taken by funding agencies. We propose solutions for these challenges based on experience gained from planning and executing a large-scale program for improving water quality of the Delaware River in eastern North America.