| Big Spring | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Missouri |
| Subdivision Type3: | Region |
| Subdivision Name3: | Ozark Plateau |
| Length Mi: | 0.2 |
| Discharge1 Location: | Big Spring (Missouri) |
| Discharge1 Min: | 236cuft/s |
| Discharge1 Avg: | 470cuft/s |
| Discharge1 Max: | 2000cuft/s |
| Source1: | Eleven Point River watershed |
| Source1 Location: | Salem Plateau, Ozark Plateau, Missouri |
| Source1 Coordinates: | http://mdc.mo.gov/fish/watershed/current/watqual/ |
| Mouth: | Current River (Missouri) |
| Mouth Location: | near Van Buren, Carter County, Ozark Plateau, Missouri |
| Mouth Coordinates: | 36.9522°N -90.9942°Whttp://nwis.waterdata.usgs.gov/mo/nwis/peak?site_no=07067500&agency_cd=USGS&format=html |
| Mouth Elevation: | 429feethttp://nwis.waterdata.usgs.gov/mo/nwis/peak?site_no=07067500&agency_cd=USGS&format=html |
Big Spring is one of the largest springs in the United States and the world.[1] An enormous first magnitude spring, it rises at the base of a bluff on the west side of the Current River valley in the Missouri Ozarks.
Located about four miles downstream from Van Buren, it is within the boundaries of the Ozark National Scenic Riverways, and its visitor facilities are managed by the National Park Service. It is a contributing resource to Big Spring Historic District, listed on the National Register of Historic Places in 1981.[2]
The average flow of 470cuft of water per second from Big Spring constitutes the second-largest tributary of the Current River. The spring is by far the largest spring in the Ozark Plateau region. The only two springs in the Ozark region that approach the size of Big Spring are Greer Spring and Mammoth Spring. The maximum discharge of Big Spring must be estimated because backwater from the Current River makes accurate high-water measurements impossible.
The spring issues from the base of a limestone bluff, churning out aqua-blue water with great force, creating whitecaps, then quickly calming to a crystal-clear channel. The spring water travels about 1000feet, where it adds itself to the Current River. The water is about 58F, and the spring is surrounded by a well-maintained park and a steep valley hillside covered in hardwood forest. Most of the known drainage basin encompasses northern areas of the Eleven Point River watershed. Big Spring is ever-increasing in size, as the groundwater continues to dissolve limestone in a vast karst system, and continues to capture streams in greater quantities. The spring is estimated to dissolve and remove 175 tons of limestone in an average day. The amounts of limestone dissolved and removed by the spring system in one year is estimated to equal a 1miles cave 30feet high and 50feet wide,[3] though that amount is dispersed among all parts of the karst system.