Paul D. Coreil
From the rich coastal waters along the Gulf of Mexico to the freshwater rivers, streams and lakes north of the coastal zone, water resources are an integral part of life in Louisiana. Historically, the challenges pertaining to water have been linked to flooding of developed areas caused by excessive rainfall or increased flow from the Mississippi River. Fresh water management began with massive efforts to protect citizens from Mississippi River floods. The supply of water from wells, rivers and bayous was considered inexhaustible.
Today, however, the focus has shifted from flood protection to declining groundwater levels and increasingly complex water quality issues. The use of water for agricultural purposes has come under closer scrutiny.
The availability of both surface and groundwater for crop irrigation helped develop the agricultural-based economies in many Louisiana parishes. Recent U.S. Geological Survey estimates indicate that the amount of groundwater used in Louisiana is approximately 1.6 billion gallons per day – with agricultural uses representing more than 50 percent of this volume. Surface water use is estimated to exceed 8.6 billion gallons per day with 4 percent representing agricultural interests. Most of the surface water pumped is used for power generation and in industry.
In recent years, irrigated cropland acreage has been increasing because marginal land is taken out of production and the most productive land is more intensively managed for maximum yields and reduced drought risks. Today, more than 1 million acres of cropland are irrigated in Louisiana with rice being the dominant crop at approximately 500,000 acres. Cotton is second representing approximately 200,000 acres. Next are corn and soybeans, each representing about 150,000 acres in irrigation.
After the record droughts of 2000 and 2001, many policymakers began paying more attention to groundwater sustainability issues. As a major user of groundwater, agriculture also became much more directly involved in water conservation policy decisions including water well registration and permitting, helping to develop a statewide groundwater management plan, and helping to develop alternatives to groundwater use.
Public interest in maintaining water quality has also increased with major emphasis on nonpoint-source pollution or general runoff from the landscape. Agriculture (crop and livestock production) and forestry have been identified as contributing to surface water impairment in some streams where watersheds are dominated by these land uses.
Under the current water quality guidelines, more than 70 percent of the state’s assessed freshwater bodies and 50 percent of the assessed estuarine (coastal influenced) water bodies are classified as impaired (not meeting water quality standards). The required Total Maximum Daily Load (TMDL) runoff reductions (the amount of runoff that a stream can receive and still meet water quality standards) needed to meet U.S. Environmental Protection Agency (EPA) standards will be challenging. In fact, many LSU AgCenter scientists and water quality specialists have serious concerns about our ability to meet these goals with the current research-based technology.
The loss of Louisiana’s coastal wetlands has averaged 25-35 square miles per year. Besides having a major effect on the economy and welfare of coastal communities, agricultural interests have experienced increased saltwater intrusion. This threatens the continued availability of freshwater for rice irrigation and crawfish production in southwest Louisiana. Additionally, the saltwater content in several north Louisiana groundwater aquifers has also limited irrigation capacity for many landowners attempting to irrigate cotton, corn and soybeans.
To address our deteriorating coastal wetlands, the LSU AgCenter has led the way in investigations using innovative plant genetic and biotechnology research. Many biologists and plant scientists see this research as a viable option in the development of natural plant varieties that can be used in coastal restoration-related vegetative plantings that will help restore eroding coastal marshes and shorelines.
To meet the challenge of sustainable use of our water resources, the LSU AgCenter has embarked on several key initiatives directly linked to attaining efficiencies in groundwater use and improving water quality. Increased research and technology transfer efforts have helped develop agricultural best management practices (BMPs) that effectively reduce cropland and animal agriculture-related runoff. Initiatives such as the Master Farmer program and the recently unveiled Master Cattle Producer program represent AgCenterled research and outreach efforts that result in voluntary BMP applications leading to improved surface water quality.
Society can have a safe, plentiful and affordable food and fiber supply and continue to enjoy the economic, social and environmental benefits of water resources. That is our goal and the goal of the farmers and farm families living and working the land throughout the state. Working together, we can achieve these objectives and help Louisiana see the full economic benefits of an abundant water supply critical to sustainable economic development.
In this issue of Louisiana Agriculture, we highlight many of the LSU AgCenter research and extension initiatives directly linked to maintaining a sustainable, high-quality water supply important to all Louisiana citizens. We delineate work being conducted on reducing runoff from agricultural landscapes, the benefits of conservation tillage, water quality challenges associated with invasive plant species and river water-linked economic development activities.
Through strong research and extension programs, the LSU AgCenter is committed to the state’s goal of achieving safe and sustainable water resources for the future.
(This article appeared in the spring 2004 issue of Louisiana Agriculture.)