First Annual Report submitted to the State; improvements in data are needed to maximize efficiency moving forward

Higher data accuracy will help South Fork Kings GSA landowners take advantage of every drop

The South Fork Kings GSA, together with the four other Tulare Lake Subbasin GSAs, submitted the first Annual Report on groundwater conditions to the CA Department of Water Resources on May 5, 2020. The Annual Report focuses on groundwater conditions in water year 2019 (Sept 2018 – Oct 2019) informed by water data, both directly measured and estimated, to update the State and stakeholders on groundwater sustainability progress.

Information includes both surface water and groundwater data that when used together, provide a picture of water use in the Subbasin. Surface water supplies provided a heavy lift to meet water demands in the Subbasin, totaling 584,906 acre-feet for the period, with local river supplies accounting for 91% of the total.

A substantial 90% of the 480,390 acre-feet groundwater extraction estimate was derived from land use information, including agricultural crop demand using imaging collected by satellite. Land use estimates using satellite imagery are useful to develop an understanding of groundwater demand but are less accurate than direct measurement tools like meters or verified crop information reported by landowners. Because groundwater extraction data is key to understanding groundwater balance, the South Fork Kings GSA is aiming to achieve higher accuracy.

Improving the accuracy of data, starting with more precise groundwater extraction measurement, will help water managers strategically manage supplies to benefit landowners while achieving sustainability under the Sustainable Groundwater Management Act (SGMA).

With an accurate read on groundwater conditions, water managers gain a firmer grasp on how much groundwater can sustainably be used. Overreliance on land use estimates can inhibit maximum groundwater use efficiency and carries a higher risk of creating pumping deficits that then must be retroactively and stringently corrected. By removing uncertainty, landowners have the opportunity to take advantage of every drop available.

An upcoming landowner survey in the South Fork Kings GSA is part of the agency’s efforts to fine tune data on groundwater supply within its service area. The focus on gathering accurate groundwater data moving forward will help the South Fork Kings GSA maximize its water supplies for stakeholders while ensuring long-term use is balanced.