The city of El Paso and Ciudad Juárez traditionally rely on both surface water from the Rio Grande and groundwater from two basins: Hueco Bolson and Mesilla Bolson. With the increase of water usage due to rapid population growth on both sides of the border, two cities are facing the challenge of shrinking groundwater due to long-term exploitation and the limitation of surface water supply because of climate and treaties. A series of strategies have been planned and adopted by two cities confronting the limited water resources condition, for example, promoting water reclamation and desalination, adopting rate structure, increasing the use of surface water, dynamic conjunctive usage of groundwater and surface water, initiating water conservation programs and importing water from other areas.
This set of diagrams shows El Paso’s conjunctive water usage of groundwater, surface water (Rio Grande) and atmospheric water (precipitation) in different water allocation scenarios. The core stands for the groundwater; the mantle stands for the surface water when the crust refers to the atmospheric water. Three circular sectors refer to three major water usage types: Irrigation, Municipal, and Industry. The width of the deep blue sectors stands for the extent to which such usage type relies on certain kind of water resource relatively.
Except for the constant 5,000 AF/yr of reclaimed water supply, under a full Rio Grande water allocation condition, the overall supply: 145,000 AF/yr comprises 60000 AF of surface water and 85000 AF of Groundwater per year. In such a scenario, surface water use is increased to save more groundwater resources for future in case of drought condition.
During drought when surface water allocation is low, water supply has to rely on higher groundwater exploitation. In such scenario, surface water supplies would drop to 10,000 AF/yr when groundwater pumped increase to 135,000 AF/yr to meet demands.
The strategy of managing conjunctive usage of groundwater and surface water in different water allocation scenarios is dedicated to offsetting the potential deficiency of a certain type of water resource by dynamically adjusting the balance of two resources. Recognizing the limitation in both groundwater and surface water, adopting such strategy is beneficial for ensuring the reliability of local basins in sustainably providing water over a long term.
