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California Water Science Center

Regional Hydrology

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Climate and Natural Resources Analysis and Planning for California's Northern Coast

The North Coast Resource Partnership (NCRP) is an innovative, stakeholder-driven collaboration among local government, Tribes, watershed groups, and interested partners in the North Coast region of California. The North Coast comprises seven counties (Figure 1), Tribal lands, major watersheds, and a planning area of 19,390 square miles representing 12% of California's landscape. The NCRP integrates long-term planning and high-quality project implementation in an adaptive management framework, fostering coordination and communication among the Region's diverse stakeholders.

The NCRP was awarded a grant from the Strategic Growth Council to develop a regional plan focused on strategies to enhance the economic, environmental and community vitality of the North Coast region. The USGS will work with Pepperwood Preserve to provide analysis and planning support for the following resource areas identified in the RFP: climate-change adaptation, forest ecology and watershed hydrology, and groundwater analyses and planning.

Figure 1. Study area of North Coast counties

Figure 1. Study area of North Coast counties.

Objective and Scope

Building on the USGS California Basin Characterization Model (Flint and others, 2013), we will rely on existing, archived data and model results to summarize historic and projected future climate, watershed, and recharge scenarios for the region at a scale of 270 m in 30-year time steps to capture long-term trends. This analysis will enable the USGS/Pepperwood Preserve team to assess potential hydrologic responses (in terms of runoff, recharge, evapotranspiration, soil moisture, and climate water deficit, which estimates stress on vegetation) to climate change at a fine spatial scale for the watersheds of the North Coast region. These results will be used to identify vulnerabilities and develop adaptation priorities for climate-change adaptation, forest ecology and watershed hydrology, groundwater analyses and planning.

Relevance and Benefits

The proposed work directly addresses several aspects of the USGS Science Strategy for the Decade, 2007-2017 (USGS Circular 1309), specifically "Understanding Ecosystems and Predicting Ecosystem Change, Climate Variability and Change." Land and resource managers in the North Coast region are seeking understanding as to the most scientifically defensible strategies for successful water supply and resource management. This study will provide tools and information on hydrologic processes and projected changes throughout the region for long-term planning strategies.

Approach

The tasks for this study address 3 priorities outlined in the request for proposals. The first of these is climate-change adaptation, where the NCRP goals are to build on existing NCRP climate adaptation work, compile and develop data, perform analyses, evaluate economic and community impacts, and support the development of draft plan sections. We will work with Pepperwood Preserve (PP) to train and closely supervise PP personnel to provide the technical analyses, and they will develop interpretations for adaptation and support the development of the NCRP regional plan.

  1. Train PP personnel to develop baseline (1951-1980) and recent (1981-2010) assessments at a regional scale: parameters to include temperature, precipitation, climate water deficit. A summary of spatial and temporal trends in climate using 30-year time steps. Products will include two regional maps and a data table summarizing regional baseline and regional trends in a numeric format.
  2. Train PP personnel to develop projected change in primary climate parameters: temperature, precipitation, and climatic water deficit, four climate scenarios (three business-as-usual with high, moderate, and low rainfall; one mitigated). Mid-century (2041-2070) and end-century (2071-2100) projections at a regional scale: parameters to include temperature, precipitation, climate water deficit. A summary of spatial and temporal trends in climate using 30-year time steps compared to baseline and recent values. Products will include three regional maps for a moderate rainfall scenario and a data table summarizing regional 30-yr trends in a numeric format for all four scenarios.
  3. Train PP personnel to provide an assessment of watersheds sensitive to climate change, and those regions unlikely to respond significantly to change on the basis of results from task 1A and 1B. Parameters under consideration will include watershed hydrology, stream flow, and fire risks. General climate adaptation principles for natural resources for the region will be developed given primary drivers and likely secondary effects.

The second task is forest ecology and watershed hydrology, where NCRP goals are the evaluation of regional forest health with a focus on water supply and quality, carbon sequestration, fuel load reduction, biological diversity, impacts related to marijuana cultivation, and economic opportunities.

  1. Watershed hydrology: Train PP personnel to examine water supply and projected changes in water supply for the entire region for baseline and recent time periods and three future scenarios in 30-year time steps. Maps of recharge plus runoff will be developed and annual time series of runoff and recharge for major basins will be provided. Major basins considered will include Klamath/Trinity, Humboldt Bay watersheds (Salt River and Mad River watersheds and other smaller watersheds draining into Humboldt Bay).
  2. Streamflow: A detailed time series of unimpaired stream flows, including base flows, will be done for the historical record and 3 future scenarios to evaluate projected changes in low flows for the Eel River, Russian River, and Redwood Creek, to support task 1.
  3. Risk of wildfire: Train PP personnel to provide a regional assessment of the change in risk of wildfire on the basis of environmental conditions for current and future projected conditions (using results from Krawchuk and Moritz 2012), considering projected climate and hydrologic stress on the landscape. The potential for increases in fuel load as a result of actual evapotranspiration and productivity will be included. Regional maps at 1-km-scale resolution of baseline and mid-century conditions will be provided with a summary table of change over time, to support task 1.
  4. Climate resilience: Train PP personnel to provide an assessment of watersheds sensitive to climate change, and those regions unlikely to respond significantly to change, to support task 1.
  5. Impacts of grow sites: A proposal will be developed on how to evaluate the potential impact of grow sites with partners as a follow-up project.
  6. Strategies for sustaining watersheds and forests. PP will make interpretations regarding additional forest, hydrology, fire, and biodiversity analyses that could support sustainability. With respect to fire, we will discuss how forest condition or fuel loading could be considered.

The third task is groundwater analyses and planning, where the goals of NCRP are to compile and analyze regional data on groundwater, and provide interpretation and suggestions for maintaining sustainable groundwater basins and mechanisms for compliance with recent groundwater legislation.

  1. Watershed-based recharge. Train PP personnel, using outputs from Task 2 above, under Watershed Hydrology, to generate a regional recharge map identifying watersheds providing high recharge value in the study area.
  2. Delineated aquifer recharge. Train PP personnel to conduct assessments for any DWR-identified groundwater basins for three future climate scenarios in contrast to the current historical record for the entire region using 30-yr averages.
  3. Strategies for sustaining groundwater. We will provide assessments regarding additional groundwater analysis that could support sustainability under SGMA, but remain outside the scope of this study.

Cooperating Agencies

Pepperwood Preserve


References

Flint, L. E., A. L. Flint, J. H. Thorne, and R. Boynton. 2013. Fine-scale hydrologic modeling for regional landscape applications: the California Basin Characterization Model development and performance. Ecological Processes 2:25.

Krawchuk, M. A., and M. A. Moritz. 2012. Fire and Climate Change in California. California Energy Commission. Publication number: CEC-500-2012-026.