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13 Cards in this Set
- Front
- Back
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How many aquifers are there in Texas and how much of our water use do they supply?
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29 aquifers and 56% of our total use.
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What is Edwards Aquifer?
Test Question |
Underground system of limestone oak pore formations 400-600 feet thick with ash, sediment and clay on top as a confining unit.
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How was it formed?
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200 million years ago the Gulf of Mexico was high and mountainous and ocean covered west Texas.
Tectonic plates shifted and the sea receded while west Texas raised and the Gulf of Mexico sank and allowed the sea to fill in the gulf. 100 Million years ago limestone sediments laid on the sea floor. Sea covering East Texas receded to present location and allowed erosion of the limestone, creating the pores. Ash from Mexican volcanic activity drifted over the area and fell on top: sediments and clay then were also laid on top as a confining unit. |
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What are three zones within the aquifer and how do they function?
Test Question |
1. Drainage Areas - Hays and 5 counties west
* Surface catches rainfall that runs into streams or filters into the shallow water table *Runoff and water table springs feed streams that flow over limestone until it reaches the Recharge Zone. 2. Recharge Zone - Limestone faults and fractures allow large amount of water into the aquifer. * Streams cross formations and go underground *Rain falls directly over the recharge zone. *Surface water reservoirs 3. Artesian Zone- Includes Comal Springs, San Marcos Springs and Barton Springs *Water flows by gravity from the recharge zone *Water is trapped in between two levels of impermeable formations *Hydraulic pressure forces the water up and out * San Marcos and Comal Springs are the Largest in the State |
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How much water does the aquifer hold?
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25-55 million acre feet.
43,560 |
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How fast does the water move within the aquifer?
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2-1,000 feet per day
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How old is the water we drink from the aquifer?
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Up to 200 years old.
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What is the annual recharge in to the aquifer?
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640,000 acre feet
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How much water is left in the aquifer when the Comal and San Marcos Springs go dry?
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95%
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Who owns the aquifer?
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No one. Land owners have rights to their groundwater not percolating water.
aka right of free capture |
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What is the rule of capture and big pump theory?
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Rules of capture allows a landowner to pump as much water as he or she chooses. The one with the biggest pump captures the most water. Landowners have the right to drill and capture without liability to neighbors.
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What are the exceptions to the Rule of Capture?
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1. Cannot maliciously take water for the purpose of injuring a neighbor
2. Cannot wantonly and willfully date it. 3. Cannon negligently cause subsidence of neighbors land 4. Can not slant drill |
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Who regulates the use of groundwater?
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Edwards Aquifer Authority and Barton Spring's/Edwards Aquifer conservation district.
*Legislature through Article 16 of the Texas Constitution passed in 1917 given the right to protect the states resources. 2. Granted authority to create water districts to control spacing of wells and regulate production *Edwards underground water district created in 1959 after drought * TEST QUESTION -1991 Sierra Club sued the US FISH and Wildlife Service for not protecting the springs and therefore the Fountain Dare and other protected species *Conserving and protecting water but no authority to limit pumping *1968 Texas Water Plan determined 450,000 acre feet annual maximum should be pumped. * Springs will dry up and constitute a taking as defined by the endangered species act 1. Replace EUWD with the EAA 2. 3. End to the right of free capture |
