Water, Water Everywhere?
Deserts are dry places, but the Mojave is hardly devoid of water. After all, water is essential to life, and the great diversity of wildlife in Mojave National Preserve suggests that there’s a substantial and accessible supply of it somewhere. But where?
Beneath the Mojave Desert is a vast system of groundwater stored in aquifers—underground layers of unconsolidated, porous, or fractured rock capable of containing a usable amount of water. The depth at which an aquifer becomes saturated is called the water table. Historically, and perhaps most familiarly, the water table of these basin aquifers are often accessed for municipal, agricultural, and industrial use by the construction and operation of wells. By contrast, a natural spring or seep occurs where the water table exceeds or breaches the ground from beneath; water naturally discharges onto the surface. In general, if the water “flows,” it’s called a spring. If it “oozes” or simply forms a wet area, it’s a seep.
Most springs and seeps in Mojave National Preserve are located along the southwest–northeast trending spine of mountains that includes the Granite, Providence, New York, and Castle mountains. They discharge from aptly named perched aquifers, which occur above the regional water table often on a valley wall or hillside, and are primarily “filled” or recharged by rain and snow melt. Because recharge comes from local precipitation, the number of springs and seeps might vary throughout the year, as well as from year to year. The wettest time of year is normally late fall through late spring. Late spring through early summer usually brings the least rainfall and the flow at natural springs steadily decreases during this time. While summer monsoons occasionally create wet conditions, their unpredictability can mean that late summer through mid-fall is the time of year with the least available surface water at Mojave springs and seeps. If a monsoon-less summer is followed by winter drought, ephemeral springs might begin to dry up.