Water Quality Standards and Assessment

Surface water management seeks to protect the quality of all waters of the state, including rivers, streams, bayous, lakes, reservoirs, wetlands, estuaries, and many other types of surface water. For more information on surface water quality data, standards, and assessment please email the Water Planning and Assessment Division.

Current Events

LDEQ's 2024 IR was submitted to EPA on March 28, 2024 and fully approved by EPA on July 2, 2024. It is now considered final and the official report for permitting and other purposes. LDEQ began the next IR cycle with the publication of a public notice on April 2, 2025 to solicit data regarding water body subsegments assessed in the 2026 IR. The public notice for the 2026 IR Rationale (includes draft water quality inventory) was published on December 30, 2025. Comments on the 2026 IR Rationale must be received no later than 4:30pm, January 30, 2026.

• Louisiana Water Quality Integrated Report
• View LDEQ's Water Quality Subsegments
• Louisiana Surface Water Monitoring and Assessment Program

Water Quality Trading

Triennial Review - Surface Water Quality Standards for Louisiana

A Long-Term Vision for Assessment, Restoration, and Protection under the Clean Water Act Section 303(d) Program

All Other Activities, Web Maps and Reports

• Water Quality Regulations and Standards - Louisiana's water quality regulations and standards form the basis for all water related activities in the state, including assessments, Total Maximum Daily Loads, permitting, and enforcement activities. 
• Water Quality Assessments - Louisiana Water Quality Inventory: Integrated Report (305(b)/303(d)) - Surface water assessments to determine needs for protection and improvement of water quality. 
• Water Quality Surveillance - LDEQ's Surveillance Division conducts ambient surface water monitoring.
• Water Data Portal - Surface water quality data collected by LDEQ for various projects at locations throughout the state.
• Quality Assurance Project Plan for the Ambient Surface Water Quality Monitoring Network (QAPP_1004_R11)
• Total Maximum Daily Load (TMDL) Program
• LDEQ Interactive Mapping Application (LIMA) - This application allows users to access a wide variety of geographic information system (GIS) layers, including water body subsegments (assessment units) and ambient monitoring sites found in the Water Data Portal. 
• Water Quality Management Plan/Continuing Planning Process
• Nutrient Reduction and Management Strategy - Learn more about what Louisiana is doing to manage nutrients in state surface waters.
• Louisiana's Fishing and Swimming Advisories - Fish consumption and swimming advisories are issued jointly by the Louisiana Department of Health, Louisiana Department of Wildlife and Fisheries, and LDEQ.
• Harmful Algal Blooms (HABs)
• DEQ Mercury Initiative - LDEQ's program to reduce and where possible eliminate mercury releases to the environment.