MKARNS Three Rivers Project

Background

The Three Rivers project is located on the McClellan-Kerr Arkansas River Navigation System (MKARNS) between the White and Arkansas Rivers, just upstream of Montgomery Point Lock & Dam in southeast Arkansas. Due to extensive modifications to the Mississippi River over the decades, the stream slope has steepened and water velocity has accelerated, causing the Mississippi River to gradually migrate into the White River. That flow then overflows into the Arkansas River.

Left unchecked, the White and Arkansas Rivers will naturally merge. When that happens, navigation pool will be lost from the Arkansas Post Canal all the way to Montgomery Point Lock & Dam. If an uncontrolled connection forms in the area and disrupts navigation for more than 100 days, it could result in more than $300 million in lost navigation benefits and commerce, as well as severe impacts to important bottomland hardwood forest and aquatic habitat.

Navigation Impacts

• Loss of navigation pool from Arkansas Post Canal to Montgomery Point Lock & Dam
• Disruption to commercial barge traffic on the MKARNS
• Long-term economic harm to ports, industries, and agricultural producers that depend on the navigation system
• Potential permanent loss of navigable depth in affected reaches

Environmental Impacts

• Severe impacts to critical bottomland hardwood forest habitat
• Degradation of aquatic habitat in the affected river reaches
• Disruption of wildlife corridors in the lower Arkansas and White River floodplains

Key Milestones

• July 2022 — Phase 1 design-build contract awarded
• October 2025 — Phase 1 construction completed (8+ months ahead of original schedule)
• December 2024 — Phase 2 contract awarded
• September 2026 — Phase 2 projected completion (tracking ~16 months ahead of contract schedule)
• January 2028 — Phase 2 contract scheduled completion (baseline)

Current Project Documents

• Three Rivers Public Fact Sheet (PDF)

June 2018 — Final Feasibility Report

• Three Rivers Final Feasibility Report
• Appendix A — Economics
• Appendix B — Hydraulics and Hydrology
• Appendix C — Engineering
• Appendix D — Clean Water Act
• Appendix E — Section 7 ESA Coordination (link pending)
• Appendix F — Cost (link pending)
• Appendix G — Real Estate (link pending)
• Appendix H — Correspondence
• Appendix I — HGM Analysis (link pending)
• Appendix J — Coordination Act Report
• Appendix K — Cultural
• Appendix L — Best Management Practices
• Appendix M — Prime Farmland
• Appendix N — Mitigation Plan

May 2018 — Feasibility Study Video & Milestone Documents

Watch: Three Rivers Feasibility Study Video

• Tentatively Selected Plan — Milestone Meeting Document

March 2017 — Draft Feasibility Report

• Three Rivers Draft Report — March 31, 2017
• Appendix A — Economics
• Appendix B — Hydrologic and Hydraulics Analysis
• Appendix C — Engineering
• Appendix D — 404(b)(1) Compliance
• Appendix E — Biological Evaluation
• Appendix F — Cost Analysis ⚠ Verify link
• Appendix G — Real Estate
• Appendix H — Correspondence
• Appendix I — Hydrogeomorphic (HGM) Analysis
• Appendix J — Coordination Act Report
• Appendix K — Cultural Resources
• Three Rivers Study — Public Comment Sheet

Related Programs

• MKARNS Navigation Program
• Civil Works Program
• SWL Water Control Data