Pajaro Valley Hydrologic Model Update, Data Collection, and Analysis for Sustainability

Science Center Objects

The Pajaro Valley is home to a billion-dollar agricultural industry, providing food and food processing services for the nation. The water for these enterprises is supplied, in large part, by the groundwater resources (aquifers) in the area. The Pajaro Valley Water Management Agency (PV Water) and the USGS have partnered to improve aquifer monitoring software, allowing better quantification and management of resources.

Pajaro Valley

Map of the Pajaro Valley

In addition to PV Water, the USGS, and other federal agencies, the data benefits water resource managers, farmers, industry, and the general public. The information helps facilitate effective water management, balancing the needs of urban, agricultural, and environmental demands.

Moreover, water agencies must fulfill requirements laid out in the Sustainable Groundwater Management Act (SGMA). Agencies that manage basins throughout California, including PV Water, are tasked with creating groundwater sustainability plans by January 2020. These plans must quantify groundwater storage and develop sustainable, operational withdrawal thresholds. Essential data about subsidence and surface-water availability will aid the region in developing sustainable management criteria and in managing water resources. Rigorous assessment of this data will enable managers to forecast potential undesired outcomes of unsustainable groundwater use.


Hydrologic model budgets and self-updating models will be developed and used to update the existing Pajaro Valley Hydrologic Model (PVHM). This work will enable regular model updates and periodic calibrations necessary for annual SGMA reporting. The newly collected data will aide future evaluation of surface-water availability and establish if subsidence is occurring in the basin. The tools will be freely available to the public, and to other model users and water managers.

Science Plan

The USGS is partnering with PV Water staff to develop tools to update the existing historical groundwater model with additional data from 2014 to 2020 and provide relevant budget data for Sustainable Groundwater Management Act (SGMA) compliance. Scientists will work with staff to calibrate the model, assist with development of SGMA metrics and milestones, and assist in developing a hydrologic budget and SGMA metric reporting tools.

They will provide a data release of model updates, install a new stream gage, and evaluate and report on subsidence in the basin. A more rigorous representation of temporal climate and surface water variability, agricultural water demands, and better documentation of model input and output, will help to provide a frame of reference for additional analysis of changing land use and potential effects of surface-water and groundwater use.