Prioritizing, monitoring, assessing, and communicating rehabilitation efforts in urbanized watersheds

Abstract

Remedying the effects of existing and growing urban areas on water quality, flow regime, and aquatic ecosystem function is a daunting challenge. Given the tens of millions of dollars committed to watershed restoration and rehabilitation and the uncertainty associated with effectiveness, there is a need to prioritize rehabilitation actions based on their potential for benefiting salmonids and watershed functions. Restoring ecosystem processes at the watershed-scale is generally assumed to have a much greater likelihood of long-term success than reach-scale rehabilitation or enhancement of individual habitat characteristics (Beechie and Bolton 1999), but most urban rehabilitation projects are still planned at the reach scale (Beechie et al. 2008). Restoration usually aims at restoring pre-disturbance conditions while rehabilitation targets short-term or local improvements when pre-disturbance conditions cannot be readily or are unlikely to be achieved (see Chap. 13). Recognizing the distinction between restoration and rehabilitation is essential to improving urbanized aquatic habitats because human structures and values constrain what can be ecologically achieved in urban and suburban areas. This chapter examines the fundamentals of prioritizing rehabilitation in urbanizing watersheds, assessing rehabilitation effectiveness, and communicating those results to multiple audiences.