Conserving Water, Critters, and Livelihoods on Georgia’s Flint River

What do peanuts, farmers, and oval pigtoe mussels have in common? They all need a healthy river and aquifer system in order to thrive in the agricultural areas of southwest Georgia.

The state of Georgia is a leading producer of peanuts and pecans, and ranks highly in sweet corn and cotton production in the United States. A combination of mild weather, arable land, and access to water has allowed a large agricultural economy to develop in the state. According to the University of Georgia’s 2011 Georgia Farm Gate Value Report, the state experienced a total agricultural production value of $12.95 billion in 2011, with chickens/eggs, cotton, and peanuts accounting for over 66% of that value. That’s a whole lot of nuts!

Corn Field in Flint River Basin Photo by Sinead Goldman

Corn Field in Flint River Basin
Photo by Sinead Goldman

With a large agricultural economy comes a large water bill, and Georgia’s farmers (the large majority of whom are individual/sole proprietorship operations) have struggled to balance their need to produce with their desire for responsible land and water stewardship.The Flint River (which you can learn about first-hand at the Flint RiverQuarium in Albany, Ga.) originates near Atlanta and flows from the Atlanta airport southwest to where it connects with the Chattahoochee River forming the Apalachicola. Drought and the growth of cities upstream in recent years have stressed the Flint River Basin.

Georgia’s farmers aren’t the only ones that feel the heat when the river runs low.

The Flint River is home to critters like the endangered oval pigtoe mussel and the Alabama shad, a species of concern. Oval pigtoe and other mussels can’t tolerate rapid and extended droughts and suffer when water levels drop. The Alabama shad has declined in the region due to upstream dams and other habitat alterations. During severe droughts the water levels can drop so much that tributaries to the Flint run dry, eliminating local fish and mussel populations and reducing biodiversity in the region.

Irrigation Pump Photo by Sinead Goldman

Irrigation Pump Photo by Sinead Goldman

Complicating matters is the fact that Georgia’s surface and underground waters have a direct connection, due to the karst geology of the region, which sits upon the Floridan aquifer system (underlying all of Florida and parts of Georgia, Alabama, and South Carolina). In regions with karst features, prevalent carbonate rocks are dissolved, leaving a porous surface through which water can easily flow. Because portions of the area aquifers have no impermeable layer separating groundwater from surface water, they are both easily rechargeable and easily drained. The interconnectedness of these water systems results in disputes between neighboring states that all rely on connected water resources.

Improvements in progress.

So how can the plants, animals, and humans of southwest Georgia and neighboring areas be ensured adequate water to support environmental systems AND the local economy?

Farmers and partner organizations are working together to develop more sustainable farming practices. The Nature Conservancy, Flint River Soil and Water Conservation District, and the USDA Natural Resource Conservation Service are among those organizations partnering to develop and analyze conservation techniques.

At the low-tech end of the spectrum, farmers can employ conservation tillage, leaving residue from last season’s crops on the field, which can reduce soil erosion and retain water content. Conservation crop rotations can also improve yield when farmers strategically plan a changing succession of crops to be planted in a field with a focus on retaining soil health.

When it comes to irrigation technology, farmers rely on irrigation from surface waters or groundwater to meet the deficit when rain does not provide sufficient moisture for crops. Farms may obtain water from tributaries to the Flint River using a pump, from underlying aquifers through wells, or both.

Once the water is out of the ground or stream, it is commonly administered to crops using a center pivot irrigation system. Center pivot systems include a sprinkler system on a long arm which “crawls” around a planted circular area to slowly water many acres. If you’ve ever looked out an airplane window and seen circular agricultural fields, you were looking at a farm using center pivot irrigation.  Early incarnations of these systems typically delivered water at high pressure, which resulted in higher energy use and a loss of water due to evaporation and wind drift.

Caney 11 Aerial Photo from Flint River Basin: by Mark Godfrey of The Nature Conservancy

Caney 11 Aerial Photo from Flint River Basin: by Mark Godfrey of The Nature Conservancy

Enter the advanced irrigation techniques being developed on the Flint. Existing center pivot systems can be retrofitted with new nozzles so that they operate at a lower pressure, saving energy and water. The nozzles can be lowered so that water falls closer to the ground, less likely to evaporate before reaching the soil.

Irrigation Nozzle Photo by Sinead Goldman

Irrigation Nozzle Photo by Sinead Goldman

If you think that’s cool (it’s okay, we do too) you’ll really love this: Variable rate irrigation systems have been developed which use global positioning system technology to shut off nozzles as they pass over areas that don’t need to be watered. This may mean mapping the field and telling the system shut off as it passes over a pond or ditch. Or, in more complex systems, a network of soil moisture sensors can tell the system which parts of the field need watering based on how wet the soil is at sample locations and depths.

According to The Nature Conservancy, the collective strategies developed by this partnership save 15 billion gallons of water annually, with a goal of 45 billion annually. Given how much water is used for agriculture, it is exciting to think of the water and energy saving possibilities if these techniques become the new standard in the future!

  Check out these websites to learn more about the groups that are making this research possible:

–          C.M. Stripling Irrigation Research Park

–          Flint River Soil and Water Conservation District

–          The Nature Conservancy- Project Overview

–          USDA Natural Resources Conservation Service

 

 *Sinead Goldman will graduate from the JHU AAP Environmental Sciences and Policy Program in May, 2013. She works at The Nature Conservancy and wrote this article following a work trip to the Flint River Basin. Many thanks to David Reckford, The Nature Conservancy’s Flint River Basin Project Director for an educational experience!*

 

Center Pivot Irrigation System Photo by Sinead Goldman

Center Pivot Irrigation System
Photo by Sinead Goldman

Center Pivot Irrigation Nozzles in ActionPhoto by Sinead Goldman

Center Pivot Irrigation Nozzles in Action
Photo by Sinead Goldman

Leave A Comment