Statement of Findings regarding the Determination of Incomplete Status of the San Joaquin Valley – Kaweah Subbasin Groundwater Sustainability Plans

California Department of Water Resources (DWR) | January 28th, 2022

The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP) conforms to specific requirements of the

The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP) conforms to specific requirements of the Sustainable Groundwater Management Act (SGMA), is likely to achieve the sustainability goal for the basin covered by the GSP, and whether the GSP adversely affects the ability of an adjacent basin to implement its GSP or impedes achievement of sustainability goals in an adjacent basin. (Water Code 10733.) The Department is directed to issue an assessment of the GSP within two years of its submission. (Water Code 10733.4.) SGMA allows for multiple GSPs implemented by multiple groundwater sustainability agencies (GSAs) and coordinated pursuant to a single coordination agreement that covers the entire basin to be an acceptable planning scenario. (Water Code   10727.) In the San Joaquin Valley – Kaweah Subbasin (Subbasin), three separate GSPs were prepared by three GSAs pursuant to the required coordination agreement. This Statement of Findings explains the Department’s decision regarding the multiple GSPs covering the Subbasin submitted jointly by the multiple GSAs. Collectively, the three GSPs and the coordination agreement are referred to as the Plan for the Subbasin. Individually, the GSPs include the following: • East Kaweah GSA Groundwater Sustainability Plan (East Kaweah GSP) – the East Kaweah GSP is implemented by a single GSA, the East Kaweah GSA. • Greater Kaweah Groundwater Sustainability Agency Groundwater Sustainability Plan (Greater Kaweah GSP) – the Greater Kaweah GSP is implemented by a single GSA, the Greater Kaweah GSA. • Mid-Kaweah GSA Groundwater Sustainability Plan (Mid-Kaweah GSP) – prepared by the Mid-Kaweah GSA. Department management has reviewed the enclosed Staff Report, which recommends that the deficiencies identified should preclude approval of the Plan. Based on its review of the Staff Report, Department management is satisfied that staff have conducted a thorough evaluation and assessment of the Plan and concurs with, and hereby adopts, staff’s recommendation and all the corrective actions provided. The Department thus deems the Plan incomplete based on the Staff Report and the findings contained herein.

Statement of Findings regarding the Determination of Incomplete Status of the San Joaquin Valley – Tulare Lake Subbasin Groundwater Sustainability Plan

California Department of Water Resources (DWR) | January 28th, 2022

The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP or Plan) conforms to specific requirements

The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP or Plan) conforms to specific requirements of the Sustainable Groundwater Management Act (SGMA), is likely to achieve the sustainability goal for the basin covered by the Plan, and whether the Plan adversely affects the ability of an adjacent basin to implement its GSP or impedes achievement of sustainability goals in an adjacent basin. (Water Code 10733.) The Department is directed to issue an assessment of the Plan within two years of its submission. (Water Code 10733.4.) This Statement of Findings explains the Department’s decision regarding the Plan submitted jointly by the El Rico GSA, Mid-Kings River GSA, South Fork Kings GSA, Southwest Kings GSA, and Tri-County Water Authority GSA (collectively, the GSAs or Agencies) for the San Joaquin Valley – Tulare Lake Subbasin (No. 5-022.12). Department management has reviewed the enclosed Staff Report, which recommends that the identified deficiencies should preclude approval of the GSP. Based on its review of the Staff Report, Department management is satisfied that staff have conducted a thorough evaluation and assessment of the Plan and concurs with, and hereby adopts, staff’s recommendation and all the corrective actions provided. The Department thus deems the Plan incomplete based on the Staff Report and the findings contained herein.

Statement of Findings regarding the Determination of Incomplete Status of the San Joaquin Valley – Tule Subbasin Groundwater Sustainability Plans

California Department of Water Resources (DWR) | January 28th, 2022

The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP) conforms to specific requirements of the

The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP) conforms to specific requirements of the Sustainable Groundwater Management Act (SGMA), is likely to achieve the sustainability goal for the basin covered by the GSP, and whether the GSP adversely affects the ability of an adjacent basin to implement its GSP or impedes achievement of sustainability goals in an adjacent basin. (Water Code   10733.) The Department is directed to issue an assessment of the GSP within two years of its submission. (Water Code 10733.4.) SGMA allows for multiple GSPs implemented by multiple groundwater sustainability agencies (GSAs) and coordinated pursuant to a single coordination agreement that covers the entire basin to be an acceptable planning scenario. (Water Code 10727.) In the San Joaquin Valley – Tule Subbasin (Subbasin), six separate GSPs were prepared by 7 GSAs pursuant to the required coordination agreement. This Statement of Findings explains the Department’s decision regarding the multiple GSPs covering the Subbasin submitted jointly by the multiple GSAs. Collectively, the six GSPs and the coordination agreement are referred to as the Plan for the Subbasin. Individually, the GSPs include the following: • Groundwater Sustainability Plan, Alpaugh Groundwater Sustainability Agency (Alpaugh GSP) – The Alpaugh GSP is managed by a single GSA, the Alpaugh GSA. • Sustainable Groundwater Management Act, Groundwater Sustainability Plan, January 2020, Delano-Earlimart Irrigation District Groundwater Sustainability Agency (Delano-Earlimart Irrigation District GSP) – The Delano-Earlimart Irrigation District GSP is managed by a single GSA, the Delano-Earlimart Irrigation District GSA, and has four management areas. • Sustainable Groundwater Management Act, Groundwater Sustainability Plan, January 2020, Eastern Tule Groundwater Sustainability Agency, Tule Subbasin (Eastern Tule GSP) – The Eastern Tule GSP is managed by a single GSA, Eastern Tule Joint Powers Authority GSA, and has five management areas. • Sustainable Groundwater Management Act, Groundwater Sustainability Plan, January 2020, Lower Tule River Irrigation District Groundwater Sustainability Agency, Tule Subbasin (Lower Tule River Irrigation District GSP) – The Lower Tule River Irrigation District GSP is managed by a single GSA, Lower Tule River Irrigation District GSA, and has three management areas. • Sustainable Groundwater Management Act, Groundwater Sustainability Plan, January 2020, Pixley Irrigation District Groundwater Sustainability Agency, Tule Subbasin (Pixley Irrigation District GSP) – The Pixley Irrigation District GSP is managed by a single GSA, Pixley Irrigation District GSA, and has three management areas. • Tri-County Water Authority, Groundwater Sustainability Plan (Tri-County GSP) – The Tri-County GSP is managed by a single GSA, Tri-County Water Authority, and has two management areas. Department management has reviewed the enclosed Staff Report, which recommends that the deficiencies identified should preclude approval of the Plan. Based on its review of the Staff Report, Department management is satisfied that staff have conducted a thorough evaluation and assessment of the Plan and concurs with, and hereby adopts, staff’s recommendation and all the corrective actions provided. The Department thus deems the Plan incomplete based on the Staff Report and the findings contained herein.

Statewide Effects of Ending Long-Term Groundwater Overdraft in California

American Society of Civil Engineers (ASCE) | September 19th, 2019

Groundwater overdraft is a major problem globally and has been a growing problem for California for decades. This overdraft is predominantly driven by the economic value

Groundwater overdraft is a major problem globally and has been a growing problem for California for decades. This overdraft is predominantly driven by the economic value of water for agricultural production and cities. Spurred by the recent drought, California passed legislation requiring the elimination of groundwater overdraft by 2040. This paper employs a statewide hydroeconomic optimization model to explore potential water supply effects of ending long-term groundwater overdraft in California’s Central Valley for several general water policies with historical and warmer–drier climates. The model minimizes agricultural, urban scarcity, and operating costs over 82 years of historical hydrologic variability, given today’s infrastructure and environmental flow constraints. The model results assess effects of overdraft and Delta policies for different climates on water deliveries, economic costs, environmental flows, water market operations, and the economic value of expanding infrastructure capacities. Prohibiting long-term overdraft leads to reduced agricultural water use and reoperations, and reduced outflows to the sea from the Sacramento-San Joaquin Delta, where water availability policies become important. In combination with a warmer–drier climate, ending overdraft further exacerbates water scarcities, increases environmental and economic costs, and increases the marginal economic value of water exports from the Delta, which are likely to worsen water conflicts and illustrate connections of California’s groundwater and surface water problems. Economically useful adaptation actions include more water transfers involving the Delta, water markets, and trades; conjunctive use of surface water and groundwater; and recycled wastewater supplies for coastal urban users.

Statistical Downscaling Using Localized Constructed Analogs (LOCA)*

American Meteorological Society (AMS) | December 2nd, 2014

A new technique for statistically downscaling climate model simulations of daily temperature and precipitation is introduced and demonstrated over the western United Sta

A new technique for statistically downscaling climate model simulations of daily temperature and precipitation is introduced and demonstrated over the western United States. The localized constructed analogs (LOCA)method produces downscaled estimates suitable for hydrological simulations using amultiscale spatial matching scheme to pick appropriate analog days fromobservations. First, a pool of candidate observed analog days is chosen by matching the model field to be downscaled to observed days over the region that is positively correlated with the point being downscaled, which leads to a natural independence of the downscaling results to the extent of the domain being downscaled. Then, the one candidate analog day that best matches in the local area around the grid cell being downscaled is the single analog day used there. Most grid cells are downscaled using only the single locally selected analog day, but locations whose neighboring cells identify a different analog day use a weighted combination of the center and adjacent analog days to reduce edge discontinuities. By contrast, existing constructed analog methods typically use a weighted average of the same 30 analog days for the entire domain. By greatly reducing this averaging, LOCA produces better estimates of extreme days, constructs a more realistic depiction of the spatial coherence of the downscaled field, and reduces the problem of producing too many light-precipitation days. The LOCA method is more computationally expensive than existing constructed analog techniques, but it is still practical for downscaling numerous climate model simulations with limited computational resources.

Storm rainfall conditions for floods and debris flows from recently burned areas in southwestern Colorado and southern California

Geomorphology (Elsevier) | April 15th, 2008

Debris flows generated during rain storms on recently burned areas have destroyed lives and property throughout the Western U.S. Field evidence indicate that unli

Debris flows generated during rain storms on recently burned areas have destroyed lives and property throughout the Western U.S. Field evidence indicate that unlike landslide-triggered debris flows, these events have no identifiable initiation source and can occur with little or no antecedent moisture. Using rain gage and response data from five fires in Colorado and southern California, we document the rainfall conditions that have triggered post-fire debris flows and develop empirical rainfall intensity–duration thresholds for the occurrence of debris flows and floods following wildfires in these settings. This information can provide guidance for warning systems and planning for emergency response in similar settings. Debris flows were produced from 25 recently burned basins in Colorado in response to 13 short-duration, high-intensity convective storms. Debris flows were triggered after as little as six to 10 min of storm rainfall. About 80% of the storms that generated debris flows lasted less than 3 h, with most of the rain falling in less than 1 h. The storms triggering debris flows ranged in average intensity between 1.0 and 32.0 mm/h, and had recurrence intervals of two years or less. Threshold rainfall conditions for floods and debris flows sufficiently large to pose threats to life and property from recently burned areas in south-central, and southwestern, Colorado are defined by: I = 6.5D− 0.7 and I = 9.5D− 0.7, respectively, where I = rainfall intensity (in mm/h) and D = duration (in hours). Debris flows were generated from 68 recently burned areas in southern California in response to long-duration frontal storms. The flows occurred after as little as two hours, and up to 16 h, of low-intensity (2–10 mm/h) rainfall. The storms lasted between 5.5 and 33 h, with average intensities between 1.3 and 20.4 mm/h, and had recurrence intervals of two years or less. Threshold rainfall conditions for life- and property-threatening floods and debris flows during the first winter season following fires in Ventura County, and in the San Bernardino, San Gabriel and San Jacinto Mountains of southern California are defined by I = 12.5D−0.4, and I = 7.2D−0.4, respectively. A threshold defined for flood and debris-flow conditions following a year of vegetative recovery and sediment removal for the San Bernardino, San Gabriel and San Jacinto Mountains of I = 14.0D−0.5 is approximately 25 mm/h higher than that developed for the first year following fires. The thresholds defined here are significantly lower than most identified for unburned settings, perhaps because of the difference between extremely rapid, runoff-dominated processes acting in burned areas and longer-term, infiltration-dominated processes on unburned hillslopes.

Storms, Floods, and the Science of Atmospheric Rivers

American Geophysical Union (AGU) | August 9th, 2011

Imagine a stream of water thousands of kilometers long and as wide as the distance between New York City and Washington, D. C., flowing toward you at 30 miles perhour.

Imagine a stream of water thousands of kilometers long and as wide as the distance between New York City and Washington, D. C., flowing toward you at 30 miles perhour. No, this is not some hypothetical physics problem—it is a real river, carrying more water than 7–15 Mississippi Rivers combined. But it is not on land. It’s a river of water vapor in the atmosphere.

Strategic Plan to Protect California Coast and Ocean 2020-2025

California Ocean Protection Council (COPC) | February 26th, 2020

Strategies for Managing the Colorado River in an Uncertain Future

Utah State University | January 11th, 2020

Colorado River managers and stakeholders face many uncertainties—issues such as climate change, future water demand, and evolving ecological priorities. Managers and st

Colorado River managers and stakeholders face many uncertainties—issues such as climate change, future water demand, and evolving ecological priorities. Managers and stakeholders are looking for new ways to communicate about uncertain future conditions, help cope with an uncertain future, and develop public policy when future conditions are highly uncertain. Historically, Colorado River managers have operated Lake Powell and Lake Mead under the assumption that the future natural flow regime of the Colorado River at Lee Ferry will resemble the previously observed regime, but most climate scientists believe that the flow regime is changing, and that future flows will be lower, more variable, and more uncertain.

Study role of climate change in extreme threats to water quality

Nature Portfolio (Springer Nature) | July 21st, 2016

With concerns about climate ‘extremes’ growing, water is often the focus — either too much or too little. That is no coincidence: climate and the hydrolog

With concerns about climate ‘extremes’ growing, water is often the focus — either too much or too little. That is no coincidence: climate and the hydrological cycle are tightly coupled, and water is essential to ecosystems and societies. But it is not just the quantity of water that matters. So does its quality.