Environmental flow limits to global groundwater pumping
Keywords:Groundwater Exchange, groundwater pumping impacts, groundwater-surface water interaction
The Reasonable Use Doctrine in California Water Law and Policy$0.00 Add to Downloads
The Reasonable Use Doctrine in California Water Law and PolicyUC Hastings Scholarship Repository | August 30, 2016...Summary
The cardinal principle of California water law is that all water rights, and all uses of water, must be reasonable. This seemingly simple...
The cardinal principle of California water law is that all water rights, and all uses of water, must be reasonable. This seemingly simple and innocuous sentence masks a world of meaning and complexity, however, because the requirement of reasonable use embraces at least four interrelated concepts.
The determination of reasonable water use is utilitarian: the law seeks to encourage relatively efficient, economically and socially beneficial uses of the state’s water resources. It is situational: the evaluation of individual reasonable use concerns not only the water right holder’s own uses but also other competing demands (both consumptive and ecological) on the water resource. The reasonable use doctrine is also dynamic: the definition of reasonable use varies as the economy, technology, demographics, hydrologic conditions, environment, and societal needs evolve. And, because all uses of water must be consistent with this interdependent and variable definition of reasonable use, the law renders all water rights fragile.
A water right that was reasonable when first recognized, and which may have been exercised reasonably for many years, may become unreasonable as hydrologic conditions change, as California’s economy evolves, as population grows and new demands for water arise, as ecological needs are better understood, and as the environmental laws that protect the state’s aquatic ecosystems and native species are applied in ways that limit the impoundment and diversion of water for consumptive uses.
Water Footprint Outcomes and Policy Relevance Change with Scale Considered: Evidence from California$0.00 Add to Downloads
Water Footprint Outcomes and Policy Relevance Change with Scale Considered: Evidence from CaliforniaPacific Institute | September 1, 2014...Summary
A new article by Julian Fulton, Heather Cooley, and Peter Gleick evaluates California’s water footprint, finding that California’s water footprint demonstrate a set...
A new article by Julian Fulton, Heather Cooley, and Peter Gleick evaluates California’s water footprint, finding that California’s water footprint demonstrate a set of vulnerabilities and policy options that do not emerge in national-level assessments. The article, published in Water Resources Management, demonstrates that water footprint assessments may find greater policy relevance when scaled to analytical units where water-related decision making occurs.
Abstract: Methods and datasets necessary for evaluating water footprints have advanced in recent years, yet integration of water footprint information into policy has lagged. One reason for this, we propose, is that most studies have focused on national units of analysis, overlooking scales that may be more relevant to existing water management institutions. The authors of Water Footprint Outcomes and Policy Relevance Change with Scale Considered: Evidence from California illustrate this by building on a recent water footprint assessment of California, the third largest and most populous state in the United States. While California contains diverse hydrologic regions, it also has an overarching set of water institutions that address statewide water management, including ensuring sustainable supply and demand for the state’s population and economy. The water footprint sheds new light on sustainable use and, in California, is being considered with a suite of sustainability indicators for long-term state water planning. Key to this integration has been grounding the method in local data and highlighting the unique characteristics of California’s water footprint, presented here. Compared to the U.S., California’s water footprint was found to be roughly equivalent in per-capita volume (6 m3d-1) and constituent products, however two policy-relevant differences stand out: (1) California’s water footprint is far more externalized than the U.S.’s, and (2) California depends more on “blue water” (surface and groundwater) than on “green water” (rainwater and soil moisture). These aspects of California’s water footprint suggest a set of vulnerabilities and policy options that do not emerge in national-level assessments. Such findings demonstrate that water footprint assessments may find more policy relevance when scaled to analytical units where water-related decision making occurs.
Atmospheric Rivers as Drought Busters on the U.S. West Coast$0.00 Add to Downloads
Atmospheric Rivers as Drought Busters on the U.S. West CoastUSGS | April 25, 2013...Summary
Atmospheric rivers (ARs) have, in recent years, been recognized as the cause of the large majority of major floods in rivers all along...
Atmospheric rivers (ARs) have, in recent years, been recognized as the cause of the large majority of major floods in rivers all along the U.S. West Coast and as the source of 30%–50% of all precipitation in the same region. The present study surveys the frequency with which ARs have played a critical role as a common cause of the end of droughts on the West Coast. This question was based on the observation that, in most cases, droughts end abruptly as a result of the arrival of an especially wet month or, more exactly, a few very large storms. This observation is documented using both Palmer Drought Severity Index and 6-month Standardized Precipitation Index measures of drought occurrence for climate divisions across the conterminous United States from 1895 to 2010. When the individual storm sequences that contributed most to the wet months that broke historical West Coast droughts from 1950 to 2010 were evaluated, 33%–74% of droughts were broken by the arrival of landfalling AR storms. In the Pacific Northwest, 60%–74%of all persistent drought endings have been brought about by the arrival of AR storms. In California, about 33%–40% of all persistent drought endings have been brought about by landfalling AR storms, with more localized low pressure systems responsible for many of the remaining drought breaks.
Increasing precipitation volatility in twenty-first-century California$0.00 Add to Downloads
Increasing precipitation volatility in twenty-first-century CaliforniaNature Climate Change | April 23, 2018...Summary
Mediterranean climate regimes are particularly susceptible to rapid shifts between drought and flood—of which, California’s rapid transition from record multi-year dryness between 2012...
Mediterranean climate regimes are particularly susceptible to rapid shifts between drought and flood—of which, California’s rapid transition from record multi-year dryness between 2012 and 2016 to extreme wetness during the 2016–2017 winter provides a dramatic example. Projected future changes in such dry-to-wet events, however, remain inadequately quantified, which we investigate here using the Community Earth System Model Large Ensemble of climate model simulations. Anthropogenic forcing is found to yield large twenty-first-century increases in the frequency of wet extremes, including a more than threefold increase in sub-seasonal events comparable to California’s ‘Great Flood of 1862’. Smaller but statistically robust increases in dry extremes are also apparent. As a consequence, a 25% to 100% increase in extreme dry-to-wet precipitation events is projected, despite only modest changes in mean precipitation. Such hydrological cycle intensification would seriously challenge California’s existing water storage, conveyance and flood control infrastructure.