an underground layer of soil, gravel, or porous rock that contains water.
a small invertebrate with four pairs of legs. Spiders, scorpions, and harvestmen – all found in the Barton Creek area – are arachnids.
a natural opening that allows water to flow through an aquifer.
land area upstream from the recharge zone where the watersheds of creeks and rivers catch rainfall.
a collection of interacting plants and animals, together with their natural environment.
an aquifer that underlies portions of nine counties in central and south-central Texas. The central section of the aquifer supplies water to Barton Springs.
the southern the southern extension of the Great Plains, which covers much of south Texas, from the Rio Grande River to the Colorado River.
changing of a liquid to a gas; for example, when water becomes water vapor.
any material in the soil or water that acts as a nutrient for plant growth.
water that seeps down from the Earth’s surface and is stored in aquifers, porous rock or soil pores.
a geological landform typified by structures created by water, such as caves, sinkholes, and highly porous rock. The Edwards Aquifer is a karst aquifer.
a nitrogen compound that is a major plant nutrient.
Nonpoint source pollution
pollution caused by sediment, nutrients, organic and toxic substances; originates from land use activities; and is carried to lakes and streams and groundwater by surface runoff.
any chemical agent used to kill specific insects or animals.
one of the primary nutrients required by plants; often is the limiting factor for the growth of aquatic plants.
Point source pollution
pollution that originates from a single, well-defined point, such as a leaking underground storage tank, a factory or a damaged sewer line.
toxic substances that enter the air or water.
the area of land where surface water enters the ground and moves into an aquifer. The aquifer is exposed at the surface at some points in the zone.
any holding area used to store, regulate or control water, may be natural or man-made.
the portion of rainfall, melted snow or irrigation water that flows across land surfaces and eventually enters a stream.
water-transported and water-deposited particles of rock, soil, or biological material.
poisonous materials that cause sickness, disease, and/or death in plants and animals.
the contamination of water by the addition of substances which degrade water quality.
the land area that contributes surface water runoff to a given point in a drainage system.