Pumping strategies in data-sparse environments: Insights from the Eastern Mancha System, Spain

The Eastern Mancha System, located within the Júcar River Basin District in eastern Spain, is one of the country’s largest carbonate aquifers. This semi-arid Mediterranean region supports extensive irrigated agriculture and faces persistent groundwater deficits, with annual withdrawals exceeding natural recharge by approximately 35 Mm 3 . This study applies the Water Balance Approach (WBA), originally developed for the Kansas High Plains Aquifer, to evaluate pumping reduction strategies in a data-sparse Mediterranean aquifer. Using 14 years (2010–2023) of water-level records from 35 monitoring points and indirect estimates of annual groundwater use, we establish a linear relationship between average annual water-level change and total pumping. This relationship is used to quantify pumping volumes required for stable water levels and to assess the impact of different management targets. The analysis shows that current pumping of 310 Mm 3 /year results in an average annual decline of 0.17 m, while near-term stabilization requires only a 1.6% reduction to 305 Mm 3 /year, while the Júcar Water Authority’s target of 275 Mm 3 /year would yield approximately 1 m/year rise in levels. These results demonstrate that modest pumping cuts could achieve stability, preserving agricultural productivity and groundwater sustainability. The study confirms that the WBA is a practical, transferable tool for rapid groundwater assessment in data-limited Mediterranean aquifers. • We assess pumping reduction strategies in the Eastern Mancha aquifer, Spain. • The Water Balance Approach is applied to a Mediterranean data-sparse environment. • The WBA is a practical tool for rapid assessment of aquifer prospects. • Annual pumping and water-level change show a strong linear relationship (R 2 = 0.78). • Stable water levels require only a 1.6% pumping reduction from current rates.