Project Monitoring to Inform the Practice of Dam Removal: pursuing important questions and getting results to practitioners

Transcription

1 Project Monitoring to Inform the Practice of Dam Removal: pursuing important questions and getting results to practitioners Matt Collins, P.H. NOAA Restoration Center Gloucester, MA

2 Why is NOAA removing dams? We believe it is an effective means to restore fish passage and coastal watershed habitat for diadromous fish Yet we know few details about the ecological effectiveness of dam removal Need to better understand ecological effectiveness to sustain public support and funding for dam removals for ecological purposes Need improved monitoring to provide the science base that advances dam removal policy, planning, and engineering

3 Common DR Monitoring Criticisms Hart et al. (2002) reported that <5% of U.S. dam removals in the 20 th century had published ecological studies. Perhaps that proportion has increased in the last 10 years (?) In any case, issues remain: Some monitoring not driven by clear research questions Some questions are very narrow and site-specific Monitoring not systematic across sites, limiting multi-site comparisons Durations inadequate to evaluate questions of interest Often not integrated with dam removal practice to influence future work

4 Integrated Monitoring Systematic project monitoring Project implementation Data capture, storage, and management Influence program priorities, project selection, and/or techniques Project analyses/ disseminate results Regional analyses by project type

5 Question-driven Monitoring We believe that dam removal monitoring, in general, should focus on questions that advance the practice NOAA trying to focus scarce monitoring dollars investigating questions important to our program and the practice in general: Ecological effectiveness Implementation-oriented NRC may be well positioned to help the community identify key questions to advance the science base for dam removal

6 Two Examples Ecological effectiveness: Penobscot River Dams Implementation-oriented: Merrimack Village Dam, NH

7 Ecological Effectiveness Penobscot project: proposing to remove the two lowermost dams in New England s second largest watershed (~ 20,000 km 2 ) to restore diadromous fisheries (11 species) Ecosystem-scale benefits anticipated Eight long-term effectiveness monitoring studies funded

8 Ecological Effectiveness Example question: Are diadromous species (e.g., river herring, shad) important in the diets of commercially important marine fish (e.g., cod, haddock)? Impact: Improved understanding of ecological effectiveness of dam removal AND implications for regional economies Funded project: Assessing Marine-Freshwater Food Web Linkages Using Stable Isotopes University of Southern Maine, Gulf of Maine Research Institute

9 Ecological Effectiveness Graphic from K. Wilson (USM) and G. Sherwood (GMRI)

10 Implementation-oriented Merrimack Village Dam (MVD) project: removed lowermost dam on a principal tributary (450 km 2 ) to the Merrimack River (~12,000 km 2 ) Approach: passive sediment management (i.e., released ~60,000 m 3 of clean sand) If consequences deemed acceptable, approach is appealing for its costeffectiveness (in some cases, only practical alternative) after Pearson et al. (2011)

11 Implementation-oriented Key question: At what rates do sediments deliberately discharged to a downstream reach, and temporarily stored there, remobilize? Impact: Improved understanding of the potential impacts of sediment accretion on stream biota, infrastructure, flood stages, recreational uses of the river, and adjacent land uses Funded project: Rates and Processes of Channel Response to Dam Removal with a Sand-filled Impoundment Boston College and NOAA

12 Implementation-oriented after Pearson et al. (2011)

13 Feedback Mechanisms

14 Successful Example Simkins dam removal site (MD) analogous to Merrimack site Sediment volume, grain size, and quality Watershed size Low gradient downstream reach Simkins project team seeking passive sediment management regulators balking Knowledge transfer mechanism: Co-workers who routinely communicate

15 Feedback Mechanisms We shouldn t rely on human relationships exclusively for knowledge transfer Are there other fields that are good analogs for this problem? Medicine?

16 Summary NRC is naturally well positioned to help dam removal practitioners improve the science base for dam removal Two areas to consider for collaboration: Identify and formulate key questions of broad importance nationally to practitioners Investigate effective mechanisms to get research results in the hands of project and program managers