A Groundwater Extraction

Total Groundwater Extractions (AF)

Water Use Sectors

B Groundwater Extraction Methods

Meters

SID, City of Rio Vista, City of Dixon and City of Vacaville all are agencies that have metered groundwater wells

Meter model type and calibration accuracy can vary an estimate of 0-5% is considered satisfactory

Electrical Records

Land Use

Groundwater Model

The Solano Integrated Hydrologic Model (Solano IHM), a gridded numerical groundwater model that characterizes surface water and groundwater uses in elements representing land across the Solano Subbasin adaptated from the Sacramento Valley Groundwater-Surface Water Simulation Model (SVSim) was used to estimate the Basin's water budget.The total agricultural water demand was quantified for various crop types simulated in the Solano IHM according to representative crop water use and root depth characteristics, soil characteristics, the reference ET demand for each month based on local weather and climate conditions, and other parameters established in the model.

Typical uncertainty associated with water demand estimates using land use, climate, surface water supply and irrigation efficiency data

Other

C Surface Water Supply

Total Surface Water Supply (AF)

Methods Used to Determine

The historical Solano IHM application and inputs used in GSP development were updated and expanded for this Annual Report using available data and information about water supplies and uses since the GSP water budget perriod. Surface Water Use was estimated from the Solano IHM and from the following Data Sources, Solano Project Diversions Reports (diversions into SID distribution system and direct deliveries from Putah South Canal),  TruePoint delivery records (deliveries from SID distribution system) and compiled eWRIMS data for water rights users where available; estimated from historical data when data not yet available

Water Source Types

D Total Water Use

Water Source Types

Water Use Sectors

E Change in Storage

Method used to calculate change in storage

To calculate annual change in groundwater storage from the groundwater level contour maps, the difference in groundwater elevation between annual spring contour maps was calculated for each of the principal aquifers (Alluvial/Upper Tehama zone and Basal Tehama zone). Changes in groundwater levels and the potentiometric surface for each year were than multiplied by a specific yield and storage coefficient, respectively. For the Alluvial/Upper Tehama zone, a spatially-varying dataset of specific yield values representing thickness-weighted average values for layers 1 through 3 in Solano IHM was used in the analysis and multiplied by spatially continuous data for the change in groundwater elevation to estimate change in storage. For the Basal Tehama zone, a single uniform storage coefficient used in the model to represent Basal Tehama aquifer properties and derived from available aquifer test data was used to multiple by change in groundwater elevations. 

F Monitoring Network Module

G PMA Module