The Watershed Sanctuary is open daily from dawn until dusk. Please respect these hours and other posted rules when logging this Earthcache. Foot traffic only; please do not drive vehicles through the entrance gates, even if they are open.
Visitors to the Watershed Sanctuary can currently observe the cave, spring, and lake, and hike a well-maintained trail through the conservation area around the cave. There are extensive plans for increasing public access and utility of the conservation area.
"The Sanctuary is an extraordinary natural site for public outreach and education to build awareness of the importance of the Illinois River watershed, water quality concerns, and ways in which the natural environment and water quality may be protected and improved. The 30-acre site will...highlight the features of the underground spring leading to a lake, limestone cave formation and abundant trees and wildlife. “ - IRWP website
Many thanks to Lauren Ray and The Illinois River Watershed Partnership for their support and assistance with this Earthcache!
What Is A Watershed?: A watershed is an area of land that drains all the streams and rainfall to a common outlet such as the outflow of a reservoir, mouth of a bay, or any point along a stream channel. The watershed consists of surface water--lakes, streams, reservoirs, and wetlands--and all the underlying ground water. Watersheds are important because the streamflow and the water quality of a river are affected by things, human-induced or not, happening in the land area "above" the river-outflow point.
The 145 mile-long Illinois River originates in the headwaters near Hogeye, Arkansas, 15 miles southwest of Fayetteville. The river continues southwesterly in Oklahoma to Lake Tenkiller. Below the Tenkiller Ferry Dam, the Illinois River flows into the Arkansas River near Gore, Oklahoma. Including its tributary streams, the Illinois River Watershed encompasses over 900 square miles in Arkansas and Oklahoma.(Source: irwp.org)
(Map Source: epa.gov)
Karst Topography and the Formation of Springs:
The Ozark region and, therefore, much of the land in the Illinois River Watershed, is classified as “karst” topography.
Karst topography refers to natural features produced on a land surface due to the chemical weathering or slow dissolving of limestone, dolostone, marble, or evaporite deposits such as halite and gypsum. Features of karst landscapes include caves, springs, disappearing streams, dry valleys, and sinkholes. Acidic groundwater moves through fractures and spaces within the rock, slowly dissolving and enlarging spaces to create larger openings and connected passages. Underground passages allow groundwater to travel long distances and re-appear as springs. Springs occur where ground water flows naturally from a bedrock or soil onto the land surface or into a body of surface water. Precipitation infiltrates into the soil and flows into the subsurface from higher elevations and generally toward a stream at a lower elevation. Weak acids found naturally in rain and soil water slowly dissolve the tiny fractures in the soluble bedrock, enlarging the joints and bedding planes. Cave Springs is the discharge area for water that has collected from a series of underground passageways formed in this way.
Recharge Area
A groundwater recharge area is a surface land area where water that eventually enters an aquifer (an underground reservoir) is first absorbed into the ground.
The total recharge area for Cave Springs is 12,515 acres (19.6 square miles). The Cave Springs recharge area encompasses lands that are included in the municipalities of Cave Springs, Rogers, Lowell, and Springdale.
The predominant topography of this recharge zone (and much of the land included in the Illinois River Watershed) is karst, and this has a significant impact on the sensitivity of the groundwater to surface and ground pollutants. Because water quality issues are of such pressing concern to everyone who relies on the Illinois River, care is taken to protect recharge areas within the watershed.
Note on the map below how Interstate 49 (formerly I-540) was re-routed during construction, curving East to avoid encroaching on the direct recharge area for Cave Springs.
Earthcache Logging Requirements:
To log this Earthcache, please send an email with answers to the following questions:
- Observe the cave from both sides of the gated enclosure. How many distinct cave openings are visible?
- In your own words, why might water flowing through the local karst topography be more susceptible to surface pollutants than water flowing through topography with loamy or sandy soil?
- The Direct Recharge Zone for Cave Springs covers 10 square miles. Assuming the average flow from this spring is 4 million gallons/day (it varies seasonally), how much groundwater does each square mile in the direct recharge zone contribute to the spring each day?
Sources:
“Groundwater Tracing and Recharge Area Delineation Summary Report, Cave Springs Cave, Cave Springs, Arkansas,” Ozark Underground Laboratory, January 2015.