Dataset Overview
This dataset compiles data on the costs of environmental mitigations related to fish exclusion for 35 hydropower projects based on documents obtained from the U.S Federal Energy Regulatory Commission (FERC). Data for all measures and their associated project-specific information, including installed and hydraulic capacities, were manually extracted from environmental impact statements and/or environmental assessment (EIS/EA) documents. All data were consolidated in a comma-separated (.csv) file, referred to as the Cost of Fish Exclusion Technologies for Hydropower Database.
Measures intended to mitigate the entrainment of fish into hydroelectric facilities (e.g., turbines, sluice gates, diversion valves) can be found within publicly available environmental impact statements (EIS) and environmental assessment (EA) documents associated with FERC hydropower license dockets in the FERC eLibrary (https://elibrary.ferc.gov/eLibrary). Data used in this report were obtained from two sources: ORNL’s Costs of Mitigating the Environmental Impacts of Hydropower Projects data set and directly from the FERC eLibrary. Oladosu et al. (2021) compiled an extensive database of 182 EIS/EA documents extracted from the FERC eLibrary from 1996 to 2018, which included 54,000 protection, mitigation, and enhancement (PM&E) measures along with associated projected capital costs and facility characteristics (available on HydroSource as Werble et al. 2021). For this report, PM&E measures were filtered to include those pertaining to aquatic species (Tier 1) and projected capital costs greater than zero.
To identify measures from this subset related to positive barrier fish exclusion, a search string consisting of the key words “screen, screens, bar, bars, spacing” was used. Measures that did not include physical construction (i.e., planning, development, or studies) or were associated with pumped storage hydropower facilities were removed from the search results. Additional data were manually extracted from EIS/EA documents associated with these measures as needed. The Oladosu et al. (2021) data set was supplemented by manual extraction of data from EIS/EA documents associated with hydropower licenses found within the FERC eLibrary that included PM&E measures related to fish exclusion. These included documents from 2009, 2016, and 2018 to 2021, with September 13, 2021, as the last date of accession.
For each PM&E measure pertaining to fish exclusion, data were extracted that pertained to facility type (conventional relicense, CR; non-powered dam, NPD; or new stream development, NSD), projected capital costs for construction (henceforth referred to as capital costs), installed power capacity (kW), maximum hydraulic capacity flow (cfs), and the size of screen openings (in.). Installed power capacity and hydraulic capacity were limited to the powerhouses or generation units that were targeted for fish exclusion mitigation and summed if multiple units were involved; capacities may differ between mitigation measures for projects with multiple powerhouses or generation units. Capital costs were adjusted to US dollars in 2020 values using RSMeans historical cost indices (RS Means, 2019) for the original project and the 2020 estimate (239.1). One project (FERC Docket 2322) reported costs in US dollars in 2021 values, for which an index of 257.5 was used to convert to US dollars in 2020 values. Some mitigation measures addressed exclusion from non-hydropower generation structures (e.g., exclusion from sluice gates, diversion dams). Therefore, data pertaining to these measures were excluded from analyses involving power generation (installed capacity or theoretical head heights) but included in analyses involving flow.