April is Springs Protection Awareness Month. There are more than seven hundred identified springs in the State of Florida. All of which have become threatened in varying degrees by anthropogenic activities and other factors. As such, many of the water management districts (WMDs) have established “Spring Teams” comprised of in-house experts charged with evaluating and applying a variety of techniques such as regulation, monitoring, research and development, restoration, and education to relieve stresses, which have diminished water quantity and quality observed at the springs.
What is actually is a “spring”? In general terms, a spring is a window to an aquifer. It is the point at which the water surface (water table or potentiometric surface) within an aquifer or aquifers breaches the land surface. Springs can be localized points or lengthy lines of seepage and can vary from a trickle of flow to providing enough water to supply a small metropolitan area. There are five spring types that are generally categorized based on the location of the springhead. These include: depressional springs; contact springs; fault springs; joint/fracture springs; and karst springs.
Just as springs types are categorized based on the location of the springhead, springs are also classified on the average spring discharge and referred to in terms of “magnitude”. For example, of the greater than seven hundred twenty (720) documented springs in the State of Florida, there are approximately thirty-three (33) documented “first magnitude springs”. The Table 1 is adapted from O.E. Meinzer, 1927. Essentially, the higher the magnitude of the spring the greater the average spring discharge. This does not imply that greater quantities of water can be drawn from the spring without damaging the ecosystem of the springshed.
Table 1. Spring magnitude classification based on average spring flow discharge
Traditional approaches to springs protection and restoration have focused on areas proximal to the spring or spring group or the entire springshed. The major problem with large scale approaches to spring management is twofold. First, the cost to implement such approaches is enormous and the state and water management districts could never allocate those types of funds for this effort. Second, a broad scale approach to springshed management would require local governments to enact regional land use restrictions, regulations and possible removal of existing infrastructure, such as septic tanks and industrial facilities. It has been shown that they are not willing to undertake this type of effort that would affect numerous landowners and business. If the state intends to follow traditional approaches to springs protection and restoration, the funding will be rapidly depleted and, in the big picture, ineffective in resolving issues such as water quality and minimum flows and levels.
Rather than a large scale, “catch-all” approach, WRA believes a surgical approach to hydrogeologic evaluation and solution implementation to (1) identify the specific primary source areas of nutrient and related recharge water within a springshed and (2) develop strategies for cost-effective improvement of the quantity and quality of spring systems. The WRA’s Principal Hydrogeologist, Michael Alfieri, P.G., along with Dr. Sam Upchurch, P.G. have developed a methodology is streamlined and provides a spatially focused, economical means for spring protection using proven methodologies that provides:
- An analysis of the origin/headwater hydrochemical facies of specific areas (i.e., “hot spots”) where nutrient and associated recharge are contributing to the discharge from the spring vent(s);
- Protection zone delineation based on this source geochemical analysis and appropriate karst groundwater flow analysis, not simply proximity to the spring;
- Recommendation of remedial design solutions to improve the quantity of the spring discharge and water quality at the spring vent(s); and
- Identification of best management practices to improve the quantity and quality of spring discharge.
Unlike the traditional approaches, the methodology is cost-effective with springshed-specific solutions that are more palatable for the local officials and regulators. Being more economically conscious, the approach can allow for multiple springsheds to be evaluated for the cost of one springshed with the traditional approach.
WRA was recently approved by the SWFWMD to evaluate the effectiveness of our approach by investigating the origin/headwater hydrochemical facies of Rainbow Springs Group, as well as delineate a protection zone based on this source geochemical analysis and appropriate karst groundwater flow analysis. If found to be effective and economical, it is planned that the final two prongs of the approach will be evaluated following the first phase of the project.
Written by M.C. Alfieri, P.G., P.Hg., CGWP
1. Meinzer, O.E., 1927, Large Springs in the United States: U.S. Geological Survey Water-Supply Paper 557.
2. Lawrence, F.W., and S.B. Upchurch, 1976. Identification of geochemical patterns in ground water by numerical analysis. In E.A. Zaleem (ed.), Advances in Groundwater Hydrology, America Water Resources Association, p. 199-214.
Lawrence, F.W., and S.B. Upchurch, 1982. Identification of recharge areas using geochemical factor analysis. Ground Water, 20:680-687. Jones, G.W., S.B. Upchurch, and K.M. Champion, 1996. Origin of nitrate in ground water discharging from Rainbow Springs, Marion County, Florida. Brooksville, Southwest Florida Water Management District, 155 p.
Upchurch, S.B., and K.M. Champion, 2003. Delineation of Spring-Water Source Areas in the Ichetucknee Springshed. Tallahassee, Florida Department of Environmental Protection, Division of State Lands.