Water and Environmental

The mission of the water and environmental section is to gain a better understanding of the hydrologic systems of Louisiana, particularly through increased knowledge of the properties of the state's aquifers. Besides research into Louisiana aquifers - especially how they interact with each other and with the state's rivers, lakes, and wetlands - research is also performed into water quality and how natural and man made pollutants are distributed and move within the aquifers, as well as interactions with surface water bodies. The results of this research into the state's hydrologic systems allows the LGS to provide effective technical assistance/support to various stakeholders of Louisiana water resources, thus aiding in Louisiana's management of this valuable resource.

Projects

Evaluation of Water Permit Requests

This three year project funded by DNR, now in its second year, requires LGS to provide DNR with unbiased recommendations for water permit requests.  Such applications are mostly for withdrawal of water from running surface water resources submitted to the DNR Secretary pursuant to Act 955 of 2010.  Applications are generally received by DNR from other state agencies, parish governments, etc. and are evaluated mainly to determine environmental consequences resulting from the action proposed in the concerned application.

Regional Groundwater Model Of Central Louisiana Aquifers

PI: Douglas Carlson

This modeling project will include three major aquifers in the central portion of Louisiana: Evangeline, Jasper and Catahoula Aquifers. Each of these aquifers is composed of interbedded layers of sand and clay. This project is in its very initial stage. Present work is a start on aquifer characterization to build a conceptual model of this aquifer which is necessary prior to the construction of the numerical groundwater model: the MODFLOW finite-difference model. Hydraulic conductivity values have been determined for about 550 wells which have had specific capacity tests completed. These results include over 70 values for each of the three major aquifers. Recharge rate has been determined from analysis of stream discharges for eight watersheds over the past 36 years, which includes about 180 individual years of discharge records.

Regional Groundwater Model Of The Chicot Aquifer

PIs: Douglas Carlson, Riley Milner and Clint Willson (LSU Department of Civil Engineering)

This project involves characterization of the aquifer in order to build a conceptual model of it. The hydraulic conductivity of this aquifer has been determined for about 600 wells that have had specific capacity tests completed. Recharge rate has been determined from analysis of stream discharge for 18 watersheds over the past 36 years, which includes about 460 individual years of discharge records. In addition, work on the stratigraphy and porosity of these aquifers is nearing completion. Contacts between regionally significant sand and clay layers have been determined from examination of over 1000 geophysical logs. In the southeastern parishes there is top confining clay and clay between upper and lower portions of the Chicot Aquifer. In the southwest, Calcasieu and Cameron Parishes, there are three sands: 200 foot, 500 foot and 700 foot, plus clays above and between these sands. Currently about 3500 values of porosity have been determined from analysis of about 70 sonic, neutron and density logs throughout southwest Louisiana. In addition, work on relating hydraulic conductivity to sand textures within a large scope of depositional sources has begun. All of this hydrogeologic information is being incorporated in both regional and parish size models of the Chicot Aquifer.

Regional Groundwater Model Of The Mississippi Alluvial Aquifer

PI: Douglas Carlson

This project is in its very initial stage. Present work is a start on aquifer characterization to build a conceptual model of this aquifer which is necessary prior to the construction of the numerical groundwater model: the MODFLOW finite difference model. The hydraulic conductivity of this aquifer has been determined for about 440 wells that have had specific capacity tests completed. Recharge rate has been determined from analysis of stream discharges for six watersheds over the past 36 years, which includes about 200 individual years of discharge records.

Regional Groundwater Model Of The Southern Hills Aquifer System

PI: Thomas Van Biersel

This modeling project will include the three major aquifer systems in the southern hills regions of southeastern Louisiana: the Chicot Equivalent, Evangeline Equivalent and Jasper Equivalent aquifer systems. Each of these aquifers systems are composed of several sand and clay layers. This project is in its very initial stage. Present work is a start on aquifer characterization to build a conceptual model of this aquifer which is necessary prior to the construction of the numerical groundwater model: the MODFLOW finite difference model. Hydraulic conductivity values have been determined for about 550 wells which have had specific capacity tests completed. These results include over 100 values for each of the three major aquifer systems. Recharge rate has been determined from analysis of stream discharges for 14 watersheds over the past 36 years, which includes about 425 individual years of discharge records.

Regional Groundwater Model Of The Sparta Aquifer System

PI: Douglas Carlson; Co-PI’s: Thomas Van Biersel, Riley Milner

This modeling project involves three major aquifers in the northwest to north central portion of Louisiana: Cockfield, Sparta and Carrizo-Wilcox Aquifers. Each of these aquifers is composed of interbedded layers of sand and clay. This project is in its initial stage. Present work is a start on aquifer characterization to build a conceptual model of this aquifer which is necessary prior to the construction of the numerical groundwater model: the MODFLOW finite difference model. Hydraulic conductivity values have been determined for about 1100 wells which have had specific capacity tests completed. These results include over 125 values for each of the three major aquifers. Recharge rate has been determined from analysis of stream discharges for 25 watersheds over the past 36 years, which includes about 500 individual years of discharge records. In addition, initial work on the stratigraphy and porosity of these aquifers has been completed. Contacts between major aquifers and aquitards have been determined in this initial examination of about 3150 geophysical logs. This includes five contacts that have been located in over 1000s geophysical logs: Sparta-Cane River contact (2169), Cane River-Carrizo-Wilcox contact (2025), Carrizo-Wilcox – Midway (1758), Cook Mountain-Sparta (1749), and Cockfield-Cook Mountain (1382). Currently about 3700 values of porosity have been determined from analysis of about 40 sonic logs throughout northern Louisiana. These results include about 1500 values of porosity for both Sparta and Carrizo-Wilcox aquifers.