Oklahoma Water Facts
- Oklahoma is underlain by 22 major groundwater basins containing
approximately 390 million acre-feet of water in storage, though only one-half
of that amount may be recoverable. Groundwater is the prevalent
source of water in the western half of the state.
- The state's largest groundwater basin, the Ogallala Aquifer in
western Oklahoma, contains 90 million acre-feet of supply--enough
to cover the entire state two feet deep.
- 44% of all water used in the state is from groundwater
- Oklahoma has approximately 55,646 miles of shoreline along lakes and ponds.*
- Oklahoma contains approximately 1,401 square miles of water area
in its lakes and ponds (larger than the state of Rhode Island).*
- Oklahoma has approximately 167,600 miles of rivers/streams.*
- Oklahoma's longest river is the Beaver/North Canadian River (752 miles); the Red River is the second longest (570 miles).*
- Oklahoma's largest lake in surface area is Eufaula (105,000 acres);
Lake Texoma is second (88,000 acres). The state's largest lake in
conservation storage is Texoma (2.6 million acre-feet of water);
Eufaula is second (2.3 million acre-feet).
- Average annual lake evaporation in Oklahoma ranges from 48 inches
in the extreme east to 65 inches in the southwest, numbers that
far exceed the average yearly rainfall in those areas.
- 56% of all water used in the state is from surface water.
*based on USGS 1:24,000 scale
- In 2005, 1,746,080 acre-feet of water was withdrawn for all uses; 63% from surface water sources and 37% from groundwater sources.
- Public water supply (41% of total use) is the number one use of water in Oklahoma; irrigation (32%)
is second, followed distantly by livestock and aquaculture (12%).
- Groundwater accounts for 73 percent of total irrigation
water use in Oklahoma.
- The majority of the state's surface water (approximately 54 percent)
is used for public water supply.
- The approximate number of stream water permits on file at the
OWRB is 2,600; the approximate total allocated stream water use
in Oklahoma is 2.6 million ac-ft/year.
- The approximate number of groundwater permits on file at the OWRB
is 10,000; the approximate total allocated groundwater use in Oklahoma
is 3.2 million ac-ft/year.
- Evaporation and percolation preclude immediate use of approximately
80 percent of Oklahoma stream water.
- Each year, approximately 10.5 million acre-feet of water flows into Oklahoma through its two major river basins,
the Red and Arkansas. An average of almost 36 million acre-feet flows out of the state each year.
- Almost half of flood-related deaths occur in vehicles, primarily
when people drive into flooded highway dips or low-drainage areas
- There are approximately 40,000 structures in Oklahoma that reside
within the boundaries of the regulatory floodplain, yet less than
10,000 of these are covered by flood insurance.
- One inch of rain falling on a 160 acre field delivers 4,344,680
gallons of water, or 13.3 acre feet. It would take just over 4 miles
of 80,000 gallon capacity railroad tank cars to transport this amount
of water, which would weigh more than 18,000 tons.