Central Coast

Persistent spatial structuring of coastal ocean acidification in the California Current System

Nature Portfolio (Springer Nature) | May 31st, 2017

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA e

The near-term progression of ocean acidification (OA) is projected to bring about sharp changes in the chemistry of coastal upwelling ecosystems. The distribution of OA exposure across these early-impact systems, however, is highly uncertain and limits our understanding of whether and how spatial management actions can be deployed to ameliorate future impacts. Through a novel coastal OA observing network, we have uncovered a remarkably persistent spatial mosaic in the penetration of acidified waters into ecologically-important nearshore habitats across 1,000 km of the California Current Large Marine Ecosystem. In the most severe exposure hotspots, suboptimal conditions for calcifying organisms encompassed up to 56% of the summer season, and were accompanied by some of the lowest and most variable pH environments known for the surface ocean. Persistent refuge areas were also found, highlighting new opportunities for local adaptation to address the global challenge of OA in productive coastal systems.

Physical and Hydrologic Assessment of the Carmel River Watershed California

California State University, Monterey Bay (CSUMB) | November 1st, 2004

The Carmel Watershed is a terrestrial jewel in the California landscape. Its forested headwaters harvest rain from the Pacific storms each winter, providing a nat

The Carmel Watershed is a terrestrial jewel in the California landscape. Its forested headwaters harvest rain from the Pacific storms each winter, providing a natural cascade of resources enjoyed by human residents and the broader ecosystem. Although the Carmel River is not currently listed as “impaired” by the State of California, there have been significant human impacts that could lead to impaired waters. These impacts are now recognized and defined in this report so that remediation and future management policies can be developed. This report is one facet of the Carmel Watershed Assessment orchestrated by the Carmel River Watershed Conservancy. We assess the physical and hydrologic components of the watershed, chiefly focusing on two major classes of problems, water quantity and excess sediment. Both of these issues are important when considering human needs and the needs of the broader ecosystem, including endangered aquatic and riparian species. The Carmel Watershed has finite annual rainfall as its only water resource. That resource is currently stretched too thin, leaving new urban, suburban, rural, and industrial development in and around the watershed at odds with pre-existing water appropriation and environmental requirements (e.g., SWRCB, 1995a; 1995b). Certain kinds of common land-uses and road designs supply excess sediment above natural background rates. Some of the major problems in the watershed are summarized below, in no particular order. Demand for water far exceeds water supply, leading to many related subordinate problems, including diminished surface water for endangered steelhead trout. Extensive urbanization exists within the regulatory 100-year floodplain and in the dam-failure inundation zone. Excess sediment is generated from a very large number of dirt roads, some of which are abandoned, some of which out of compliance with grading ordinances, but most of which are clearly within regulations. Nearly all sub-road drainage culverts are undersized, leading to downstream erosion, whether related to dirt roads, paved roads, or highways. Excess sediment is generated by a great number of bare road cuts on dirt roads, paved roads, and highways. Excess sediment is generated in the Los Chupines and Sycamore Creek drainages by soil slip, gullies, unstable stream banks, and roads. Many of those issues are related to cattle impacts. Excess sediment is generated in a great number of incised streams that have tall, exposed banks. San Clemente Dam is unsafe owing to sediment burden and proximity to active faults. Decommissioning the San Clemente Dam will likely lead to a significant shift in river morphology and flood response, owing to the restoration of historic bedload transport rates. Los Padres Dam is rapidly infilling with sediment and is also close to active faults. Watershed impairment is the result of incremental, permitted, changes that have a large cumulative impact on the watershed. Closer adherence to the Carmel Valley Master Plan (CVMP, 1996; Appendix C) and County ordinances will foster resource sustainability and aesthetic living conditions. Among the salient points in that document are the following guidelines for development (CVMP, 1996). 1. Preserve the rural character of the Carmel Valley 2. Protect all natural resources with emphasis on biological communities, agricultural lands, the Carmel River and its Riparian corridor, air quality and scenic resources. We note that the large-scale negative impacts we describe in the Carmel Watershed mainly resulted from the cumulative effects of small, insignificant, permitted landscape or hydrologic alterations (e.g., Dunne et al., 2001). With that in mind, guidelines for sustainable resource use could begin with an agreed upon ultimate level of resource use, depletion, or degradation, beyond which, no further landscape or hydrologic alterations will be permitted. Using water supply as an example, the best strategy for sustainability is to determine the total cumulative resource usage, and then stop permitting further requests for resource use when the agreed upon cumulative impact is met—the concept of water rights appropriation. This same “cumulative impact” management strategy could be applied to other cumulative watershed impacts, such as total miles of dirt road per square mile of watershed area, or total area of impervious cover per square mile of watershed area. These strategies can be applied once a cumulative impact target has been established upon sound science, and codified by stakeholder agreement. Considering that the cumulative negative impacts in the watershed are the net result of innumerable, insignificant modifications, we can predict that innumerable, small positive restorative efforts in the watershed would eventually produce large positive impacts on watershed health including water quality and quantity.

Piloting a Water Rights Information System for California

Center for Law, Energy, and the Environment (CLEE) | July 15th, 2021

California’s complex water management challenges are growing and intensifying. Systemic stressors like the more frequent and severe droughts and floods driven by climat

California’s complex water management challenges are growing and intensifying. Systemic stressors like the more frequent and severe droughts and floods driven by climate change are only making it harder to respond. Accordingly, California needs to dramatically improve the ability of local, regional, and State entities to make agile and effective water management decisions. We believe doing so will require enhanced understanding of our water resources and how they align with the needs of a range of agencies and stakeholders. Water rights data provide a crucial opportunity for advancing this understanding. We find that modernizing water rights data is feasible, affordable, and can increase transparency and clarity for better decision-making.

Piru Basin Groundwater Sustainability Plan Final (Revised)

Fillmore and Piru Basins Groundwater Sustainability Agency | July 8th, 2024

Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13

Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13

Plan writing as a policy tool: instrumental, conceptual, and tactical uses of water management plans in California

Journal of Environmental Studies and Sciences (Springer) | February 24th, 2022

Numerous environmental regulations require organizations to codify prospective activities in a written plan. However, evidence suggests that many plans are never implemen

Numerous environmental regulations require organizations to codify prospective activities in a written plan. However, evidence suggests that many plans are never implemented, raising questions about why public agencies continually require plans, whether mandating plans allows agencies to meet their policy aims, and what additional purposes plans serve. Adopting concepts from literature on research utilization, we develop a plan use typology, defining instrumental use as occurring when the requirement to write a plan directly addresses a stated policy problem, conceptual use as occurring when the requirement to write a plan indirectly addresses a policy problem by raising awareness of an issue or improving governance capacity, and tactical use as occurring when the requirement to write a plan serves a political or symbolic purpose unrelated to solving the policy problem. We then apply the typology to four California statutes that require local and regional utilities to write water management plans. We first assess the statutes to identify the goals underlying the requirement to write a plan and assess what plan uses are emphasized in guidance documents and the written plans themselves. Lastly, we interview the plan writing organizations to capture their perspectives on the value and limitations of these plans. We find that legislators turn to plans to support instrumental and conceptual goals but that the plans themselves and the way they are used by authoring agencies primarily serve conceptual and tactical uses, suggesting a disconnect between the policy goals underlying plans and their actual use.

Poleward shift of the major ocean gyres detected in a warming climate

American Geophysical Union (AGU) | February 24th, 2020

Recent evidence shows that wind‐driven ocean currents, like the western boundary currents, are strongly affected by global warming. However, due to insufficient observa

Recent evidence shows that wind‐driven ocean currents, like the western boundary currents, are strongly affected by global warming. However, due to insufficient observations both on temporal and spatial scales, the impact of climate change on large‐scale ocean gyres is still not clear. Here, based on satellite observations of sea surface height and sea surface temperature, we find a consistent poleward shift of the major ocean gyres. Due to strong natural variability, most of the observed ocean gyre shifts are not statistically significant, implying that natural variations may contribute to the observed trends. However, climate model simulations forced with increasing greenhouse gases suggest that the observed shift is most likely to be a response of global warming. The displacement of ocean gyres, which is coupled with the poleward shift of extratropical atmospheric circulation, has broad impacts on ocean heat transport, regional sea level rise and coastal ocean circulation.

Population exposure to pre-emptive de-energization aimed at averting wildfires in Northern California

Environmental Research Letters (IOP) | August 26th, 2020

Recent extreme fire seasons in California have prompted utilities such as Pacific Gas and Electric to pre-emptively de-energize portions of the electrical grid during per

Recent extreme fire seasons in California have prompted utilities such as Pacific Gas and Electric to pre-emptively de-energize portions of the electrical grid during periods of extreme fire weather to reduce the risk of powerline-related fire ignitions. The policy was deployed in 2019, resulting in 12 million person-days of power outages and widespread societal disruption. Retrospective weather and vegetation moisture data highlight hotspots of historical risk across northern California. We estimate an average of 1.6 million person-days of de-energization per year, based on recent historical climate conditions and assuming publicly stated utility de-energization thresholds. We further estimate an additional 70% increase in the population affected by de-energization when vegetation remains abnormally dry later into autumn—suggesting that climate change will likely increase population vulnerable to de-energization. Adaptation efforts to curtail fire risk can be beneficial, but efforts to prepare affected populations, modernize the grid, and refine decision-making surrounding such policies have high potential to reduce the magnitude of negative externalities experienced during the 2019 de-energization events.

Postfire Sediment Mobilization and its Downstream Implications Across California, 1984–2021

American Geophysical Union (AGU) | August 27th, 2024

Potential impacts of increased coastal flooding in California due to sea-level rise

Climatic Change (Springer) | November 24th, 2011

California is likely to experience increased coastal flooding and erosion caused by sea-level rise over the next century, affecting the state’s population, infrastructu

California is likely to experience increased coastal flooding and erosion caused by sea-level rise over the next century, affecting the state’s population, infrastructure, and environment. As part of a set of studies on climate change impacts to California, this paper analyzes the potential impacts from projected sea-level rise if no actions are taken to protect the coast (a “no-adaptation scenario”), focusing on impacts to the state’s population and infrastructure. Heberger et al. (2009) also covered effects on wetlands, costs of coastal defenses, and social and environmental justice related to sea-level rise. We analyzed the effect of a medium-high greenhouse gas emissions scenario (Special Report on Emissions Scenarios A2 in IPCC 2000) and included updated projections of sea-level rise based on work by Rahmstorf (Science 315(5810): 368, 2007). Under this scenario, sea levels rise by 1.4 m by the year 2100, far exceeding historical observed water level increases. By the end of this century, coastal flooding would, under this scenario, threaten regions that currently are home to approximately 480,000 people and $100 billion worth of property. Among those especially vulnerable are large numbers of low-income people and communities of color. A wide range of critical infrastructure, such as roads, hospitals, schools, emergency facilities, wastewater treatment plants, and power plants will also be at risk. Sea-level rise will inevitably change the character of California’s coast; practices and policies should be put in place to mitigate the potentially costly and life-threatening impacts of sea-level rise.

Potential local extirpation of an imperiled freshwater mussel population from wildfire runoff

Western North America Naturalist | December 17th, 2022