2025 USACE Flood Risk Management Alternatives

source: 2025 USACE Revised Draft Environmental Impact Statement  (RDEIS)

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2025 USACE Pearl River Flood Risk Management Alternatives

Alternative A1: Non-structural measures such as elevations and floodproofing plus Canton Club Levee.  A1 is the only proposed alternative with a positive benefit cost ratio but the Corps has removed this alternative from future consideration. Click to view more information about A1

Alternative D1: Similar to the "One Lake" project, this alternative includes excavation of 9 river miles; a new dam placed south of Interstate 20; and new levees at Canton Club (NE Jackson), McLeod (NE Jackson), Cany Creek (S Jackson), and Richland Creek. The RDEIS notes that, due to the loss of riverine habitat, this alternative will "cause major long-term negative impacts to fisheries and aquatic resources.” Alt D1 could also have "potential direct impacts to water supply due to the coexistence of known HTRW (Hazardous, Toxic, Radiological Waste) sites and probable exposure to contaminants within the ponded area created by the proposed weir.” At a Projected First Cost of $873-$913 million, this alternative could cost almost double the $475 million USACE Section 902 cost limit. Click to view more information about D1

Alternative E1: Includes excavation of 9 river miles and new levees at Canton Club, McLeod, Cany Creek, and Richland Creek. Does not include new dam. The USACE writes in their 2025 RDEIS Summary: "Of the remaining implementable alternatives assessed, the Alternative E1 (without weir) minimizes implementation risks, maximizes the difference between monetized benefits and costs, and satisfies the USACE Planning Principles and Guidelines (P&G) criteria of completeness, effectiveness, efficiency, and acceptability. Accordingly, the Alternative E1 without weir could be considered the preliminary NED plan." (The NED plan is the one that reasonably maximizes net benefits across all relevant categories) Click to view more information about E1

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Alternatives Cost Comparison

​According to the 2025 Revised DEIS, Alternative D1 ("One Lake") costs approximately $150 million more to build and $500,000 more per year to maintain than Alternative E1 (no dam/lake), but does not provide any additional flood risk reduction or recreational benefits. 

Costs*	Alt D1 ("One Lake")	Alt E1 (D1 w/out dam)	Alt A1 (non-structural)
Project First Cost	$873-$917 million**	$708-$753 million**	$16 million
Annual Operation and Maintenance	$700,000	$200,000	-
Damages Reduced	$19.7 million	$19.8 million	$1.8 million
Recreation Benefits	$5.4 million	$5.4 milion	-
Total Benefits	$25.2 million	$25.2 million​	-
Net Benefits	(-$11--$12.8 million)	(-$3.8--$5.6 million)	$194,700
Benefit/Cost Ratio***	0.7***	0.9-0.8***	1.3
Local Cost Share****	​$305-$320 million, plus $700k annual costs****	$247-$263 million, plus $200k annual costs****	$5 million****

*reference: 2025 USACE RDEIS
**U.S. Congress Water Resources Development Act "Maximum Project Cost" limit is $475 million. Alternatives D1 and E1 are above the "Maximum" limit and would require Congressional approval for a project cost increase. 
***If a project's Benefit/Cost Ratio is less than 1.0, the project's costs outweigh the benefits
​***​*Rankin Hinds Pearl River Flood and Drainage Control District, the local project sponsor, must contribute 35% of total project costs

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Alternatives Project Features 

Features*	Alt D1 ("One Lake")	Alt E1 (D1 without dam)
Lake Surface Area	1,556 acres	N/A
Excavation**	954 acres (9.38 MCY)**	954 acres (9.38 MCY)**
Excavation River Miles	RM 285-RM 294	RM 285-RM 294
Excavation Width	500-2,600 feet	500-2,600 feet
Excavation Depth	0-13 feet	0-13 feet
Dam	1	None
Dam Location	RM 286.5 (south of I-20)	N/A
Dam Elevation	256 feet (current weir 250 feet)	N/A
Dam Flood Control Benefits	None	N/A
Bridge Stabilization	7 bridges	7 bridges
Hard Point in Tributaries	525 feet	525 feet
New drainage pumps	1	Not needed
Canton Club Levee (NE Jackson)	1.4 miles	1.4 miles
McLeod Levee (NE Jackson)	2.3 miles	2.3 miles
Cany Creek Levee (S Jackson)	0.75-1 mile	0.75-1 mile
Richland Levee	1.15 miles	1.15 miles
Savannah Street Wastewater Treatment wall	6,000 feet	6,000 feet
Terrestrial Habitat Mitigation	5,512-11,612 acres	-

*reference: 2025 USACE RDEIS Main Report
**Excavated fill would be placed in designated disposal areas on the protected and unprotected side of existing levees as well as other locations within the flood plain. The disposal fill areas would cover 523 acres with 9.38 MCY (million cubic yards) of excavated fill.  The excavated fill material would be used to create land areas ranging from 3-93 acres. The newly created areas could allow for expanded riverfront access, natural areas, along with recreational opportunities. Up to 1.6 MCY of fill (100 acres of fill 10 feet high) would be provided to the Rankin-Hinds Pearl River Flood and Drainage Control District for additional usage within the project area. (2025 USACE RDEIS, Appendix E, p 48-49)

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Pearl Riverkeeper asks that everyone make his or her own decision regarding the Pearl River Flood Risk Management  project using sound science and engineering.  We encourage the review and thorough analysis of all available information.  We welcome comments and feedback.  Please email Pearl Riverkeeper or visit our Facebook  for comment space.  Our publishing, or re-publishing, of anyone else's research or opinions is not an endorsement on our part of those conclusions.