Sapphires in the Ozarks: The Large Springs of Missouri

Long before Branson, before that electric company dammed the Osage, and rich people from St. Louis and Kansas City decided living at "the Lake" were the thing to do, When one spoke of the Ozarks, it was as the float fishing mecca of the Midwest, where local guides would take "flatlanders" for a week of leisurely camping via mule to the river, and then via johnboat down some of the best fishing streams known to man. The White River and its tributaries, the Jack's Fork, Current and Eleven Point, Bryant Creek, and even the upper Meramec were the goal of fishermen and women, local and city folk alike.

And what made these rivers so unusual are the large springs which feed most of them. Springs so large, and from waters so deep that droughts leave them still flowing. Missouri has eight world class first magnitude springs with over 100 cubic foot per second (cfs) average flow rates. Eighty Missouri Springs average 5 cfs, and at least 165 springs flow an average of 1 cfs. (One cubic foot of water per second will yield 646,000 gallons of water in a day.) More than 1 billion gallons of water a day comes from the flows of the largest 15 springs combined. This is on average, a rate which may increase by multiples during times of high flow, (up to ten times more for Round Spring) at record flow. Because of its remoteness from the general population, very little of this water is used for anything except as the general water supply for a few towns taking it from the rivers. Most Ozark springs are freshwater, with high calcium and magnesium contents, and are considered "hard" water; some springs on the fringes of the hills, and the glaciated plains of Missouri are actually mineral or saline (salt) springs.

This seemingly inexhaustible water supply comes from a spring's recharge area, a portion of the surrounding karst countryside, usually delineated by the use of tracer dyes, but sometimes known from unconventional means of water tracing, such as throwing straw down a sinkhole, or the pollution of the aquifer from a known point in the recharge. The longest trace, to Big Spring, largest in the state, is over 39 miles as the crow flies from the spring. Because of the nature of karst, where much of the rainfall enters the groundwater directly, Ozark springs can be broken into base flow and surge flow rates: base flow being relatively constant, and surge flow, being that water which passes through the system at high flow rates after heavy rains. The underground routes of this water can be amazingly complex, depending upon conditions in the system. Tom Aley describes it as a storage system based on milkjugs connected by straws at different elevations, instead of a uniform water "table". Where and how much water there is affects the way the system works.

Other common (but false) notions about springs and spring water abound. Though the water is clear and cold, (56 to 59 degrees Fahrenheit) this is a result of settling and coming to the same temperature as the surrounding rock, not filtration. Springwater can still contain bacteria and viruses, making it unfit to drink--even more so than surface water by some reckoning, since sunlight and aeration do not come into play underground. Many Ozark springs are blue, not as a reflection of the sky, but because a column of water without sediment is blue--but just watch one turn milky green or angry brown after a thunderstorm! And springs are not "bottomless" despite what the locals may tell you. Some are quite deep, but the old saw about putting an anvil on a rope and never hitting bottom means they had a short rope, a soft landing, or the anvil was caught by the pressure of water squirting from the spring orifice, and never hit bottom.

Springs are attractive to plants, animals and man, largely because of their constant flow as a water source. Many spring creatures can survive only in clear, cold water, with a relatively high oxygen content. Native Americans used them as camp and village sites, as did whites. Early settlers used springs as sources of refrigeration, and later, hydro power, for both mechanical and electrical energy generation. Springs were common mill sites, and picnic areas. The recreational use of springs persists even today--many of the large springs of the Ozark Plateau are now protected and used as parks, fish hatcheries, and water supplies. The swiftness of their flow makes for the popularity of spring fed rivers as canoeing streams.

Springs can be very vulnerable to disruption by man as well, through pumping of the aquifer, or contamination of an area's groundwater with urban, farm or industrial chemicals or waste. Any large scale alteration of the karst in the recharge area can cause a spring to go dry, or become polluted. Collapse of wastewater lagoons in karst, or seepage from underground pipes or tanks can be devastating to a spring system. "If it goes down, it must come up," the karst saying goes, and when it comes up, it is usually out of a spring.

Springs are truly a precious resource, one that we too often take for granted. Take time to visit these jewels of the Ozarks, and make time to make sure they remain the treasures that they are.

For more information about Ozark Springs, visit The Missouri Springs Virtual Resurgence.

2003 Jo Schaper.