Preserving the Pearl River

Preserving the Pearl River

Pearl River cypress pond
Cypress pond off main channel of Pearl in LeFleur's Bluff State Park.

The Pearl River, already dammed north of Jackson, Mississippi since 1963, faces a new threat as developers and the Rankin-Hinds Pearl River Flood and Drainage Control District look to dam the river in Jackson in the name of flood control and downtown riverfront development. 

This plan represents a threat to the river’s physical stability, wetlands, biological integrity and to the fresh water discharge to downstream reaches and coastal estuaries. In particular, damming the river could impact freshwater flows that sustain coastal marshes and oyster reefs. To add further insult to injury, a section of Jackson’s popular LeFleur’s Bluff State Park will become lake bottom.  

There are far better ways to reduce flooding in the Jackson area while minimizing the impacts on a river that is already badly in need of restoration. 

The River

oyster bushels
Unloading oyster bushels in Pass Christian, MS. Photo credit: flickr user Jennifer Cowley.

The Pearl River ranks fourth in freshwater discharge among the rivers draining the Eastern Gulf of Mexico. Estuaries in Louisiana and Mississippi at the Pearl’s mouth are highly influenced by the river’s fresh water discharge. Productive oyster reefs in the Mississippi Sound and in Louisiana’s Biloxi marshes and Lake Borgne need the salinity moderation it provides. The marshes and oyster reefs in these areas in both states took a direct hit from Hurricane Katrina and sustained considerable damage then, and again during the BP oil disaster. Oyster reef restoration projects near the mouth of the Pearl River are ongoing in both states. 

The Pearl River supports 110 species of freshwater and diadromous fish including three species of special concern: Gulf sturgeon, Pearl darter, and frecklebelly madtom. There are two federally listed threatened species that inhabit the Pearl, each having critical habitat in the Jackson reach of the river. Both are threatened by new dams:  Gulf sturgeon, and the ringed sawback turtle (which is found only in the Pearl River). Floodplain forest bottomlands along the Pearl River in Jackson, threatened by this project, include part of LeFleur’s Bluff State Park which is designated as an Important Bird Area (IBA) by Audubon Mississippi. 

The Threat

sturgeon and man jackson
Man with sturgeon in Jackson, MS, 1944. Photo credit: Mississippi Museum of Natural Science

The Pearl River is threatened by continued damming to build another lake on its main channel. The Ross Barnett Dam (1963) created a 32,000 acre reservoir for drinking water and recreation north of Jackson. Operation of that dam has changed downstream reaches in two ways. First, banks are unstable, often collapse, and contribute more sediment than the lower river can move efficiently. Second, dam operation coupled with evaporation effects cause water deficits in the lower Pearl system - in Louisiana’s Honey Island Swamp, and at the coast. Water releases at the Barnett dam during storms or hurricanes have, at times, added river water to coastal storm surges, exacerbating flooding along the lower Pearl River. 

Sea level rise on the coast, coupled with low flows, already cause salt-water intrusion in the lower basin’s cypress swamps. Climate change will accelerate this effect. 

The Rankin-Hinds Drainage District is sponsoring a 2016 Environmental Impact Statement (EIS) and feasibility study for a new dam, impounding a 1500-2000 acre in-channel lake 9 miles downstream of the existing Barnett Dam. The Greater Jackson Chamber Partnership and other economic development interests support a new lake and a riverfront for Jackson. This proposed “lake” is a dredging project to widen, deepen and straighten 7 miles of the river and place a dam at the downstream end. 

Areas immediately downstream of this new dam will feel the effects of faster flows through Jackson and have been predicted to need levee improvements if a lake is built. More bank collapse, sedimentation and channel shoaling are certain to follow, and added evaporation will place a strain on adequate downriver flows during dry periods. Further changes to the amount and timing of fresh water flows threaten coastal fisheries, especially the oyster industry. The Pearl River needs comprehensive restoration, not more dam projects.    

What Must Be Done

When the EIS and feasibility study for the new lake are published in 2016, individuals, groups, commercial and recreational fishing interests, and state agencies in Mississippi and Louisiana must participate in public meetings and be prepared to make it clear to the sponsoring Rankin-Hinds Drainage District and to the Vicksburg Corps of Engineers that another lake on the Pearl River is not acceptable. Jackson should pursue flood control solutions, like levees or floodplain buyouts, that won’t create new problems for the Pearl River.  Already, hundreds of Gulf residents, one Louisiana Parish (County) and the Mississippi Commission on Marine Resources are on record opposing the project. You can take action as well by clicking here and sending a letter to the Rankin-Hinds Drainage District.