Water science news, explainers, and statistics covering freshwater, hydrology, lakes, rivers, groundwater, ice, and Earth’s connected water systems.
Water levels in wells rise and fall because hydraulic pressure in the connected aquifer changes. Recharge can raise the level, while pumping and drought lower it. Seasonal plant use, nearby rivers and even tides or atmospheric pressure can influence certain wells. A well reading is therefore a measurement of aquifer conditions at a particular place…
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Surface water is the water visible in rivers, lakes, reservoirs and wetlands. Groundwater occupies pores and fractures beneath the land surface. Location is the clearest difference, but it is only the beginning. The two supplies move at different speeds, respond differently to weather and pollution and often flow into each other. A river can seep…
An alluvial aquifer is a water-bearing body of loose sediment deposited by flowing water. It commonly lies beneath a river valley, floodplain, terrace or alluvial fan. Sand and gravel provide connected pore spaces that can store groundwater and transmit enough of it to wells or springs. The aquifer is defined by both origin and hydraulic…
E. coli gets into lakes through fecal contamination from people and other warm-blooded animals. Rain washes waste from land into the water. Leaking sewer or septic systems can release it underground, while birds deposit feces directly on some beaches. Sand can store bacteria and return them to shallow water when waves disturb it. Most strains…
