Groundwater is the source of all perennial surface water bodies in the Sonoran Desert. Availability of groundwater is critical to plant productivity; nutrient, water, and energy flows; and wildlife. All Sonoran Desert Network parks obtain their drinking water from groundwater wells. In many parts of the American Southwest, long-term drought and human development have led to significant declines in groundwater levels at local and regional scales.
In many network parks, routine groundwater monitoring by other agencies does not occur. Groundwater declines often occur gradually, in response to the combined effects of "distributed point sources," such as wells and springs, and "nonpoint sources," such as climate, vegetation, and streams. Soil losses result in rapid runoff and reduced infiltration following wildfire, posing another threat to groundwater resources. These factors make long-term monitoring extremely important.
Knowing about the status and trends of groundwater levels helps park managers to work with regional partners and within their own parks to conserve resources and plan for future needs. For instance, local groundwater impacts associated with reductions in infiltration and storage are often related to soil loss and other changes in surface characteristics. These can be directly addressed by management actions aimed at soil conservation, fire management, and recharge enhancement. Groundwater impacts associated with stream entrenchment can be mitigated if the changes to stream morphology are identified in the early stages. Groundwater monitoring also allows managers to develop conceptual models needed to better understand actual or potential local impacts of groundwater pumping.
Measurements and Objectives
- Detect long-term changes in groundwater levels,
- Support interpretation of surface monitoring results,
- Extend regional groundwater data and regional groundwater trends to immediate park locales,
- Contribute to an understanding of water-balance dynamics at parks (including relationships between groundwater and surface water resources, biota and climate),
- Support larger scale water balance efforts by other agencies,
- Assess site suitability for riparian habitat, and
- Document water-level elevations to support legal protection of the resource.
For more information, contact Colleen Filippone, Intermountain Region Hydrologist