Thrust Areas Ecosystem Water Institute Classification Level
Water, Land Use and Ecosystems Water and Climate Water and Society Water Resources Sustainability Springs Wetlands Watersheds Aquifers Lakes Coastal Zone  Water Institute Classification 1  Water Institute Classification 2  Water Institute Classification 3  Water Institute Classification 4

Determining the Age of Ichetucknee Springs Water
Goals and Objectives
This project seeks to determine the age of water, both spatially and through time, at several of the Ichetucknee Springs. The amount of time that water spends in the Floridan Aquifer (i.e., its “average age”) is a critical factor for springshed management in general and specifically for the Ichetucknee Springs. The age of water controls natural remediation of poor-quality water as it flows through the aquifer and will influence the length of time required for detrimental land use practices to impact water quality at springs. Because age measurements are an average of all water that has mixed in the subsurface, average ages include “old” water that may have experienced some natural remediation, for example denitrification, and “young” water that likely bears the signature of human affects in the springshed (application of fertilizer, input of waste water). Remediation of impacted springs, and the protection of pristine springs, thus requires understanding the fractions of these young and old waters discharging from the springs, and how these fraction change with discharge conditions.

Four Ichetucknee Springs will be sampled twice under conditions that differ as much as possible during the time frame of the proposal (e.g. highest and lowest possible discharge). These springs will include Mill Pond, Mission, Ichetucknee, and Cedar springs, which represent two clusters of springs that have been shown to have distinct sources based on other chemical compositions (the clusters are Mission-Mill-Devil’s Eye and Ichetucknee-Cedar-Blue Hole; (Martin and Gordon, 2000)). Along with this spatial sampling, two springs from each group, Mill Pond and Cedar springs, will be sampled an additional eight times through the project to observe the rate of change of the age of the water during changing discharge conditions. Along with comparison of rates of change of age and discharge, the age of the water will also be compared with other chemical parameters (to be collected as part of an ancillary grant) that reflect changes in the chemical composition of the water during its residence in the aquifer (e.g., Fig. 1B).
Project Lead
Martin, Jonathan Bowman
Project Participants
Martin, Jonathan Bowman
Level 2: WI Assisted Project
Water Resources Sustainability
Water, Land Use and Ecosystems
Grant Award Dates
5/1/2009 to 2/28/2015