(Georgia Institute of Technology, 2007-03)
Golladay, Stephen W.; Hicks, David W.; Muenz, Tara K.
In the 1970’s agricultural water use expanded rapidly in the lower Flint River Basin resulting from the introduction of center pivot irrigation technology. The rapid expansion has raised concerns about impacts on regional stream flows essential to support aquatic fauna. Using long-term stream gage records from the USGS and climate data, we analyzed trends in stream flow in two major sub-watersheds and regional patterns of rainfall from 1940 through 2004. We observed no change in annual rainfall but seasonality changed with winters being slightly wetter. Minimum flows showed substantial declines since the development of irrigation. We attribute altered stream flows to increased regional water demand however; the demand for water is also exacerbated by long-term variations in climate and rainfall distribution.
(Georgia Institute of Technology, 2003-04)
Golladay, Stephen W.; Gagnon, Paula; Kearns, Margaret; Battle, Juliann; Hicks, David W.
A drought during the summer of 2000 caused record low flows in the lower Flint River Basin (FRB) and many perennial streams dried or became intermittent. Pre-drought surveys conducted in 1999 allowed an assessment of the impact of the drought on mussel assemblages. During 2001, 21 stream reaches which had abundant or diverse mussel assemblages were resurveyed. Where possible, study sites were classified as flowing or non-flowing during the drought. Mussel abundance at sites classified as non-flowing showed significant declines (median value 80% decrease) compared to flowing sites (median value 5% increase). Generally, greatest declines in mussel abundance occurred in the mid-reaches of the major tributaries of the lower Flint River. Declines in mussel populations appear to be associated with unusual climatic conditions and increasing demand on the area streams and the regional aquifer system for irrigation water supply.