Tehachapi Reclaimed Water Project

City of Tehachapi | September 24th, 2024

As part of the proposed project, the City would change the location of application of the secondary treated effluent produced at the Tehachapi WWTP from the agricultural

As part of the proposed project, the City would change the location of application of the secondary treated effluent produced at the Tehachapi WWTP from the agricultural fields near the Tehachapi Municipal Airport to a new location south of the Borrow Pit. Overall WWTP effluent production and WWTP throughput capacity would remain unchanged as would the time of year of application (from April to October).

Tehachapi-Cummings County Water District (TCCWD) v. Armstrong et al

Superior Court of California, County of Kern | February 25th, 1972

From An Evaluation of California’s Adjudicated Groundwater Basins by Langridge et al, UC Davis (2016): "Tehachapi Basin (1, 2) , Cummings Basin, and Brite Basin are

From An Evaluation of California’s Adjudicated Groundwater Basins by Langridge et al, UC Davis (2016): "Tehachapi Basin (1, 2) , Cummings Basin, and Brite Basin are three small groundwater basins in Kern County. Although the basins were adjudicated separately, a single entity, The Tehachapi-Cummings County Water District (TCCWD) serves as Watermaster over the three distinct groundwater basins. An interesting finding is that the Cummings adjudication was never completed. Because of this, its users rely on overlying rights with voluntary agreements, and there is no regulated curtailment of withdrawals. There are only a few big users so it is able to track its water use with relative accuracy, but the basin has significant overdraft. Two of its major users (Stallion Springs and Bear Valley) pump water from the basin that is delivered to offsite users, and they offset the export with imported water. Two-thirds of the residents within Cummings Basin are inmates at the California Correctional Institute."

Tehachapi-Cummings County Water District v. Austin et al

Superior Court of California, County of Kern | December 9th, 1970

Note from "An Evaluation of California’s Adjudicated Groundwater Basins" by Langridge et al: "Tehachapi Basin, Cummings Basin, and Brite Basin are three small ground

Note from "An Evaluation of California’s Adjudicated Groundwater Basins" by Langridge et al: "Tehachapi Basin, Cummings Basin, and Brite Basin are three small groundwater basins in Kern County. Although they were adjudicated as individual basins, the local Tehachapi-Cummings County Water District is the Watermaster for all three basins. Adjudication was deemed desirable so water users could tap into newly available imported water and also secure their water rights. To construct transmission facilities, a federal loan was needed, and adjudication was necessary to assure repayment."

Temescal Basin Groundwater Sustainability Plan

Temescal Basin Groundwater Sustainability Agency | January 27th, 2022

Wishing to provide a framework for cooperative groundwater management and SGMA compliance, the City of Corona (Corona), City of Norco (Norco), and the Home Gardens Coun

Wishing to provide a framework for cooperative groundwater management and SGMA compliance, the City of Corona (Corona), City of Norco (Norco), and the Home Gardens County Water District (HGCWD) executed a Memorandum of Understanding (MOU) in March 2017 establishing the Temescal Basin Groundwater Sustainability Agency (Temescal GSA). In August 2017, the Temescal GSA became the GSA for the Basin by submitting a formation notice to DWR. While Corona is leading this effort, the GSP will be developed jointly among the three agencies, with coordinated implementation toward sustainable management. Due to size, the file has been divided into four parts. Part 1, Part 2, Part 3, Part 4

Temporal and Spatial Patterns of Groundwater Recharge Across a Small Watershed in the California Sierra Nevada Mountains

Frontiers in Water (Frontiers) | May 17th, 2022

Mountain-block groundwater recharge is a crucial freshwater source in arid to semiarid watersheds worldwide; yet its quantification is difficult due to (1) hydrogeologica

Mountain-block groundwater recharge is a crucial freshwater source in arid to semiarid watersheds worldwide; yet its quantification is difficult due to (1) hydrogeological heterogeneities especially in bedrock-dominated regimes, (2) drastic altitudinal ranges in climate, land use and land cover, and (3) mixing with deep groundwater derived from adjacent basins (i.e., interbasin groundwater flow). In this study, we test the utility of soil water-balance (SWB) modeling to quantify mountain-block groundwater recharge in the South Fork Tule River watershed in the California Sierra Nevada Mountains. This 1,018 km2 watershed is instrumented with 3 USGS stream gages that allow for the development of a refined recharge (i.e., baseflow) calibration dataset via multi-objective optimization-based hydrograph separation. The SWB model was used to compute groundwater recharge and other water balance components at a daily time step using a 30-m grid cell size for a 40-year (1980–2019) study period. Mean annual recharge and runoff were estimated at 3.7 in/yr (3.0 m3/s) and 1.4 in/yr (1.2 m3/s), respectively, with modified Nash Sutcliffe Efficiency indices of 0.61 between baseflow and SWB-derived recharge, and 0.90 between hydrograph separation- and SWB-derived runoff. There is a strong correlation between annual recharge and rainfall (Pearson R = 0.95, p < 0.001) which attests to short residence times in the unsaturated zone and the immediate impact of droughts in 1990, 1999, and 2013. However, results of a modified Mann-Kendall trend analysis indicate no directional trends in recharge or runoff throughout the study period. Parameter sensitivity analyses reveal a persistent overprediction of recharge over baseflow that is particularly pronounced in the upper reaches of the watershed. This is likely related to the SWB model only considering soil characteristics at the surface and not simulating the fate of potential recharge below the root zone where it may be impeded from reaching the aquifer by shallow, impermeable bedrock. This limitation should be considered carefully for future water supply projections in this and comparable bedrock-dominated settings.

Temporal changes in the vertical distribution of flow and chloride in deep wells

National Groundwater Association (NGWA) | July 4th, 2005

The combination of flowmeter and depth‐dependent water‐quality data was used to evaluate the quantity and source of high‐chloride water yielded from different depth

The combination of flowmeter and depth‐dependent water‐quality data was used to evaluate the quantity and source of high‐chloride water yielded from different depths to eight production wells in the Pleasant Valley area of southern California. The wells were screened from 117 to 437 m below land surface, and in most cases, flow from the aquifer into the wells was not uniformly distributed throughout the well screen. Wells having as little as 6 m of screen in the overlying upper aquifer system yielded as much as 50% of their water from the upper system during drought periods, while the deeper parts of the well screens yielded 15% or less of the total yield of the wells. Mixing of water within wells during pumping degraded higher‐quality water with poorer‐quality water from deeper depths, and in some cases with poorer‐quality water from the overlying upper aquifer system. Changes in the mixture of water within a well, resulting from changes in the distribution of flow into the well, changed the quality of water from the surface discharge of wells over time. The combination of flowmeter and depth‐dependent water quality data yielded information about sources of high‐chloride water to wells that was not available on the basis of samples collected from nearby observation wells. Changing well design to eliminate small quantities of poor‐quality water from deeper parts of the well may improve the quality of water from some wells without greatly reducing well yield.

Temporal concentrations of Quaternary ammonium compounds in wastewater treatment effluents during the COVID-19 pandemic, 2020–2021

Elsevier | November 19th, 2024

Temporal variability in irrigated land and climate influences on salinity loading across the Upper Colorado River Basin, 1986-2017

Environmental Research Letters (IOP) | January 19th, 2024

Temporary Restraining Order in Kings County Farm Bureau et al v. California State Water Resources Control Board

Superior Court of California, County of Kings | July 11th, 2024

Temporary Urgency Change Petition for February 1, 2023, through March 31, 2023

California State Water Resources Control Board (SWRCB) | February 13th, 2023