Aquatic Resources
Fresh and marine water systems are home to a
tremendous diversity of fish, amphibians, aquatic plants, invertebrates, and
microorganisms.
Aquatic ecosystems and their native biota are affected by pollution, introduction of non-native species, over-harvesting, water diversions, and physical modifications of habitat. Most importantly, freshwater rivers and lakes are more heavily affected by human activities than any other habitat types in California in terms of species composition and overall diversity.
California faces water demands that are anticipated to exceed supplies, with shortfalls increasing from an estimated 1.6 million acre feet in 1995 to 2.4 million acre feet in 2020. As the value of water for power generation continues to grow, electric utility companies will increasingly become competitors for water, even though their requirements for water are relatively small compared to other sectors. Conflicts are anticipated, especially in dry years, and there is concern that inflexible commitments to electricity production could affect water supply. Therefore, there is a clear need to develop cooling alternatives (e.g., dry cooling, use of degraded water) capable of ameliorating the situation.
Accordingly, the Aquatic/Water Resources
subsection of the PIEREA focuses on the effects of electricity generation on water supply
and quality and on biological resources associated with California's streams,
rivers, lakes, estuaries and ocean. The program's aim is to develop technologies,
strategies and tools that will decrease the demands of power generation on freshwater
supplies and reduce impacts on water quality and aquatic organisms.
WATER RESOURCES
The Water Resources subsection of the PIEREA focuses on opportunities to reduce the demand
on fresh water supplies from power generation, especially from those facilities
utilizing wet cooling technology. Power plant water conservation measures
currently being evaluated by the PIEREA program include the use of dry cooling,
spray enhancement for dry cooling, use of degraded water supplies for power plant cooling,
and updated cooling tower water quality parameters.
There are three significant issues concerning hydropower generation and protection of
aquatic resources. The first issue is how hydropower facilities and the associated
dams alter or eliminate natural ecological and hydrological functions in streams and
rivers within the state riverine aquatic systems, contributing significantly to the
decline of aquatic species. Adverse impacts from hydropower generation
include fatality from impingement (i.e., trapping aquatic organisms in intake
screens) and entrainment (i.e., passing aquatic organisms through cooling systems
and pumping intake valves and turbines); blockage of fish movement and migration;
fragmentation of ecosystems; and alterations in normal stream flows and
temperatures. A better understanding of the affected environment, the interaction of
generation facilities with the environment, and advances in analytical and
mitigation measures will help reduce such environmental impacts.The second issue addresses the cumulative effects of multiple hydroelectric facilities on aquatic resources and terrestrial habitats. Such impacts are difficult to evaluate, because of a lack of site-specific information and appropriate methodologies.
The third issue addresses the effects of the electric power industry restructuring and the re-licensing of hydropower projects by the Federal Energy Regulatory Commission (FERC). These regulatory mandates are expected to affect hydropower operation as well as environmental management and stewardship of land and water resources by owners, including the potential for changes in peak power production and a shift in resource priorities. There is a pressing need to better identify and understand these impacts, and, as appropriate, develop alternative means of mitigation.
Finally, the impacts of thermal power generation in California on aquatic resources is another important issue. Thermal generation, especially those facilities utilizing once-through cooling technology, can adversely affect aquatic resources through entrainment (i.e., passing aquatic organisms through cooling systems), impingement and thermal discharge. Other types of thermal generation within California may also adversely impact aquatic resources as well, mainly through wastewater discharge and the resulting water quality degradation.
To address these issues the PIEREA staff is currently developing two roadmaps. The first roadmap will identify research and development needs that are necessary to address the three hydropower-related issues. The second roadmap will address the research and development issues associated with thermal generation impacts on aquatic resources. Specifically, the two roadmaps will explore research conducted on assessing and mitigating impacts, opportunities for future research and co-operative and cost-sharing opportunities. Issues and research opportunities identified by these roadmaps will serve as the basis for future PIEREA research efforts and projects.
Highlights
- Comparison of Alternative Cooling Technologies for California Applications, Economic, Environmental and Other Tradeoffs.
- Evaluation of Design, Cost and Performance of Spray Enhancement for Dry Cooling.
Contact:
Joe O'Hagan
Email: johagan@energy.state.ca.us