A Groundwater Extraction

Total Groundwater Extractions (AF)

Water Use Sectors

Rural Domestic, Golf Course, and Small Public Water System

B Groundwater Extraction Methods

Meters

Metered Municipal Wells

The level of accuracy is rated on a qualitative scale of low, medium, and high. The Metered groundwater extraction accuracy rating is high.

Electrical Records

Land Use

Land use volumes were calculated using Land IQ land use data in conjection with OpenET.

The level of accuracy is rated on a qualitative scale of low, medium, and high. The Land Use accuracy rating is medium.

Groundwater Model

Other

Rural Domestic use was estimated using an updated aerial photo review, Small Public Water Systems use was estimated using eAR reporting and aerial photo review, Golf Course use was estimated using acreage and liturature water duty factors. All three were scaled annually by water year type.

The level of accuracy is rated on a qualitative scale of low, medium, and high. The Rural Domestic, Golf Course and Small Public Water Systems groundwater extraction accuracy rating is medium.

C Surface Water Supply

Total Surface Water Supply (AF)

Methods Used to Determine

Metered

Water Source Types

D Total Water Use

Water Source Types

Water Use Sectors

Rural Domestic, Golf Course and Small Public Water System

E Change in Storage

Method used to calculate change in storage

From PDF page 39-40 of Report [SECTION 3.5: Change in Groundwater in Storage (§ 356.2[b][5])]:

Annual changes in groundwater elevation in the Alluvial Aquifer and the Paso Robles Formation Aquifer for WY 2024 are derived from a comparison of fall groundwater elevation contour maps from one year to the next. For this analysis, fall 2023 groundwater elevations were subtracted from the fall 2024 groundwater elevations resulting in maps depicting the changes in groundwater elevations that occurred during WY 2024 (see Figure 14 [Alluvial Aquifer] and Figure 15 [Paso Robles Formation Aquifer]). The WY 2024 maps are based on data from 59 Paso Robles Formation wells and 9 Alluvial Aquifer wells. 

The groundwater elevation change maps presented above represent a volume change within the Alluvial Aquifer (Figure 14) and the Paso Robles Formation Aquifer (Figure 15) for WY 2024. The volume change inferred from the groundwater elevation change maps represents a total volume, including the volume displaced by the aquifer material and the volume of groundwater stored within the void space of the aquifer. The portion of void space in the aquifer that can be used for groundwater storage is represented by the aquifer storage coefficient (S), a unitless factor, which is multiplied by the total volume change to derive the change in groundwater in storage. Based on work completed for the GSP, S is estimated to be 7 percent in the Paso Robles Formation Aquifer.  The aquifer storage coefficient value used for the Alluvial Aquifer is 20 percent.

F Monitoring Network Module

G PMA Module