Financing Water Supply and Sanitation in a Changing Climate

Pacific Institute | October 22nd, 2020

Human-caused climate change is real and accelerating, creating new challenges for all aspects of freshwater management. Important gaps in our understanding of these chall

Human-caused climate change is real and accelerating, creating new challenges for all aspects of freshwater management. Important gaps in our understanding of these challenges include both the complications climate change poses for planning, implementing, and sustaining water supply and sanitation (WSS) systems, especially for the poor; and the links between these systems and the emissions of greenhouse gases that worsen the overall climate problem. This paper addresses these gaps. 

Finishing the All-American Canal

Scientific American | September 1st, 2020

Work on the All-American Canal is going forward so rapidly that the great 80-mile ditch and its appurtenant features will be ready to de­liver irrigation water to the Im

Work on the All-American Canal is going forward so rapidly that the great 80-mile ditch and its appurtenant features will be ready to de­liver irrigation water to the Imperial Valley in southeastern California some time during the first half of 1938. The waterway is being dug across a normally desert region that once formed the wa­ter bed of the prehistoric northern ex­tension of the Gulf of California, as we know it today. Paradoxically, that far­ flung section of the Gulf was transform­ ed into a generally barren and arid region by the very river that is to be tapped to assure the continued agricul­tural productivity · of soil that can be made amazingly fruitful by irrigation.

Fire (plus) flood (equals) beach: coastal response to an exceptional river sediment discharge event

Nature Portfolio (Springer Nature) | March 9th, 2022

Wildfire and post-fire rainfall have resounding effects on hillslope processes and sediment yields of mountainous landscapes. Yet, it remains unclear how fire–flood se

Wildfire and post-fire rainfall have resounding effects on hillslope processes and sediment yields of mountainous landscapes. Yet, it remains unclear how fire–flood sequences influence downstream coastal littoral systems. It is timely to examine terrestrial–coastal connections because climate change is increasing the frequency, size, and intensity of wildfires, altering precipitation rates, and accelerating sea-level rise; and these factors can be understood as contrasting accretionary and erosive agents for coastal systems. Here we provide new satellite-derived shoreline measurements of Big Sur, California and show how river sediment discharge significantly influenced shoreline positions during the past several decades. A 2016 wildfire followed by record precipitation increased sediment discharge in the Big Sur River and resulted in almost half of the total river sediment load of the past 50 years (~ 2.2 of ~ 4.8 Mt). Roughly 30% of this river sediment was inferred to be littoral-grade sand and was incorporated into the littoral cell, causing the widest beaches in the 37-year satellite record and spreading downcoast over timescales of years. Hence, the impact of fire–flood events on coastal sediment budgets may be substantial, and these impacts may increase with time considering projected intensification of wildfires and extreme rain events under global warming. Wildfire is an important factor in hillslope erosion and sediment yields of mountainous and forested

Fire and Water: Assessing Drinking Water Contamination After a Major Wildfire

American Chemical Society (ACS) | August 2nd, 2021

We investigated patterns of volatile organic compound (VOC) contamination in drinking water systems affected by the California 2018 Camp Fire. We performed spatial analys

We investigated patterns of volatile organic compound (VOC) contamination in drinking water systems affected by the California 2018 Camp Fire. We performed spatial analysis of over 5000 water samples collected over a 17 month period by a local water utility, sampled tap water for VOCs in approximately 10% (N = 136) of standing homes, and conducted additional nontargeted chemical analysis of 10 samples. Benzene contamination was present in 29% of service connections to destroyed structures and 2% of service connections to standing homes. A spatial pattern was apparent. Tap water in standing homes 11 months after the fire contained low concentrations of benzene in 1% of samples, but methylene chloride was present in 19% of samples, including several above regulatory limits. Elevated methylene chloride was associated with greater distance from the water meter to the tap, longer stagnation time, and the presence of a destroyed structure on the service connection; it was inversely associated with certain trihalomethanes. Nontargeted analysis identified multiple combustion byproducts in the water at 2/10 homes. Our findings support the hypothesis that pyrolysis and smoke intrusion from depressurization contributed to the benzene contamination. Further research is needed to test the hypothesis that methylene chloride may be generated from the dehalogenation of disinfection byproducts stagnating in galvanized iron pipes.

Fire influence on land–water interactions in aridland catchments

Oxford University Press (OUP) | January 9th, 2025

Wildfires have increased in size, frequency, and intensity in arid regions of the western United States because of human activity, changing land use, and rising temperatu

Wildfires have increased in size, frequency, and intensity in arid regions of the western United States because of human activity, changing land use, and rising temperature. Fire can degrade water quality, reshape aquatic habitat, and increase the risk of high discharge and erosion. Drawing from patterns in montane dry forest, chaparral, and desert ecosystems, we developed a conceptual framework describing how interactions and feedbacks among material accumulation, combustion of fuels, and hydrologic transport influence the effects of fire on streams. Accumulation and flammability of fuels shift in opposition along gradients of aridity, influencing the materials available for transport. Hydrologic transport of combustion products and materials accumulated after fire can propagate the effects of fire to unburned stream–riparian corridors, and episodic precipitation characteristic of arid lands can cause lags, spatial heterogeneity, and feedbacks in response. Resolving uncertainty in fire effects on arid catchments will require monitoring across hydroclimatic gradients and episodic precipitation.

First annual report of the Mojave Basin Area Watermaster 1993-1994

Mojave Basin Area Watermaster | February 28th, 1995

First flush analysis of urban storm runoff

Science of the Total Environment (Elsevier) | July 3rd, 2003

Stormwater runoff was monitored on 13 separate urban watersheds, which were chosen to represent distinct types of residential and industrial development, along with vario

Stormwater runoff was monitored on 13 separate urban watersheds, which were chosen to represent distinct types of residential and industrial development, along with various watershed characteristics. A total of 38 storm events were monitored to investigate the first flush phenomenon. The first flush phenomenon may be defined as the initial period of stormwater runoff during which the concentration of pollutants is substantially higher than during later stages. The magnitude of the first flush phenomenon, and if it actually occurs, was calculated using a method of data analysis which results in determining the ‘event mean concentration’ (EMC). The magnitude of the first flush phenomenon was found to be greater for some pollutants (e.g. suspended solids from residential areas) and less for others (e.g. chemical oxygen demand from industrial areas). No correlation was observed between the first flush phenomenon and the antecedent dry weather period, however, the first flush phenomenon was greater for smaller watershed areas.

First Supplement to Bulletin No. 11, San Joaquin County Investigation, Basic Data, Calaveras and Littlejohns Units, 1953-1955

California State Water Resources Control Board (SWRCB) | June 30th, 1955

Fish & Wildlife Groundwater Planning Considerations

California Department of Fish and Wildlife (CDFW) | June 6th, 2019

In 2014, California passed the Sustainable Groundwater Management Act (SGMA) (AB1739, SB 1168, SB 1319), authorizing local groundwater sustainability agencies (GSAs) to d

In 2014, California passed the Sustainable Groundwater Management Act (SGMA) (AB1739, SB 1168, SB 1319), authorizing local groundwater sustainability agencies (GSAs) to develop groundwater sustainability plans (GSPs) for a subset of California’s alluvial aquifers. To comply with SGMA, GSAs must achieve sustainable groundwater management, defined by SGMA as the avoidance of locally-defined undesirable results. To achieve sustainability, GSAs must develop and implement effective groundwater management plans that consider the interests of all beneficial uses and users of groundwater, including environmental users of groundwater. [Water Code § 10723.2.] In many groundwater basins, fish and wildlife that rely on groundwater are among these beneficial uses and users. Many sensitive species and habitats comprise groundwater dependent ecosystems (GDEs), which are natural communities that rely on groundwater to sustain all or a portion of their water needs. The unsustainable use of groundwater can impact the shallow aquifers and interconnected surface waters on which GDEs depend and may lead to adverse impacts on fish and wildlife. As trustee for California’s fish and wildlife resources, CDFW intends to engage as a stakeholder in groundwater planning processes (where resources are available) to represent the groundwater needs of GDEs and fish and wildlife beneficial uses and users of groundwater. The information provided here is intended to help local groundwater planners, groundwater planning proponents and consultants, and CDFW staff work together to consider the needs of fish and wildlife when developing groundwater management plans and implementing SGMA. The document includes three categories of groundwater planning considerations: Scientific Considerations Management Considerations; and Legal, Regulatory, and Policy Considerations. Links to additional guidance and considerations developed by CDFW and other organizations that address the impacts of groundwater pumping on GDEs and depletion of interconnected surface water can be found at the end of this document. Except to the extent that this document directly references existing statutory or regulatory requirements, use of these groundwater planning considerations is not mandated under law and should not be interpreted as a rule, regulation, order, or standard for local groundwater plans. Practical application of these considerations must be based on the best available information and groundwater basin-specific conditions.

Fish & Wildlife Groundwater Planning Considerations: Freshwater Wetlands

California Department of Fish and Wildlife (CDFW) | June 6th, 2019

 In 2014, California passed the Sustainable Groundwater Management Act (SGMA) (AB1739, SB 1168, SB 1319), authorizing local groundwater sustainability agencies to develo

 In 2014, California passed the Sustainable Groundwater Management Act (SGMA) (AB1739, SB 1168, SB 1319), authorizing local groundwater sustainability agencies to develop groundwater sustainably plans for a subset of California’s alluvial aquifers. This document provides considerations to assist local groundwater sustainability agencies in avoiding or minimizing adverse impacts to freshwater wetland beneficial uses and users of groundwater in local groundwater management planning and implementation. The information provided is intended to help local groundwater planners, groundwater planning proponents and consultants, and California Department of Fish and Wildlife (CDFW) staff work together to protect wetlands as a public trust resource.