Change in Groundwater Storage. The water budgets calculate change in groundwater storage using the data described in this article. For deep percolation of precipitation, the water budgets use the United States Geological Survey’s Basin Characterization Model (May 2017; Retrieved October 2020). For subsurface inflows and outflows, modeling was coordinated between the GSAs and the flows across Management Area boundaries are consistently accounted for across the water budgets. Change of groundwater in storage in each Management Area is calculated by 1) developing water level elevation contour maps using representative xxxxx for each reporting period, 2) computing a change in elevation between reporting periods, 3) computing the volume of aquifer this represents, and 4) multiplying a storage coefficient value by the aquifer volume to compute the volumetric change in storage (positive or negative relative to the previous reporting period).
Change in Groundwater Storage. The change in groundwater storage for the Delta‐Mendota Subbasin is shown below in a series of graphs depicting groundwater use and annual change in groundwater storage from 2015 – 2019 with cumulative change in storage. Figure X also shows the change in storage by principal aquifer. Change in Storage (Acre‐F eet ) Principal Aquifer 2019 WY Change in Storage Upper Aquifer 729,394 Lower Aquifer 5,216 Total 82,591 Commented [LD7]: This table auto‐populated by DMS Commented [LD8]: Note that the color bars denote water year type (a reporting requirement). The legend got cut off in this graphic and in the next graph Commented [LD9]: This map would use the same base map as the groundwater extraction map but the call‐out boxes would have two numbers, likely different colors, representing the change in storage in each principal aquifer. Commented [LD10]: Revise subsection titles to match GSP titles 6. Plan Implementation The following describes each of the six GSP Group’s progress toward implementing their respective plan, including progress towards achieving interim milestones and the implementation of projects and management actions. Cumulatively, these efforts provide the required advancement towards achieving and maintaining groundwater sustainability in the Delta‐Mendota Subbasin.
Change in Groundwater Storage. The information presented in this white paper provides a suggested methodology and protocols for consistent change in groundwater storage data throughout the Xxxx Subbasin. The intent of this white paper is to advance the dialogue between participating members of the KGA on the development of a coordination agreement required under the Sustainable Groundwater Management Act (SGMA). The information presented herein is draft and subject to the input and revision from members of the Coordination Committee. xxx.xxxxxxxxxxxxxx.xxx GEI Consultants, Inc. 0000 Xxxxxxxxxx Xxxxxx, Xxxxx 000, Xxxxxxxxxxx, XX 00000 000.000.0000 fax: 000.000.0000 Water Budget Components Water budgets estimate change in groundwater storage by comparing supplies to consumptive uses and outflows. This section explains the supply and consumptive use components that need to be considered when developing a water budget for the Xxxx Subbasin. Figure 1 shows the summary equation. Supply can be calculated by documenting and adding together water supply inputs into the Xxxx Subbasin, which include: • Kern River. • Minor streams. • CVP imports. • SWP imports. • Precipitation. • Groundwater inflows from small watersheds. • Groundwater inflows from the Tule Subbasin. • Groundwater inflows from Tulare Lake Subbasin. • Produced water from oil extraction. • Withdrawals from groundwater storage (groundwater extractions). Consumptive use can be calculated by documenting and adding together consumptive uses and outflows, which include: • Managed habitat evapotranspiration. • Undeveloped land evapotranspiration. • Soil moisture evapotranspiration. • Agriculture evapotranspiration. • Groundwater outflows to small watersheds. • Groundwater outflows to Tule Subbasin. • Groundwater outflows to Tulare Lake Subbasin. • Municipal consumptive use (municipal use minus municipal discharge). • Evaporation during energy production. • Contributions to groundwater storage (deep percolation). This white paper discusses methods that can be used to measure or estimate change in groundwater storage. Other components of the water budget are discussed in other white papers.
Change in Groundwater Storage. The network will provide sufficient data for the GSAs to estimate the change in annual groundwater in storage.
