False River Restoration
LDWF, Partners Seek To Bring Back False River Lake To Its Former Fishing Glory
story by TRey Iles, LDWF Public Information
On the surface, False River is what comes to mind when you think about a near perfect Louisiana recreational lake. The 3,212 acre water body located in Pointe Coupee Parish, about 35 miles northwest of Baton Rouge, is a great place to spend the day boating, skiing, fishing, riding jet skis, swimming and enjoying the Sportsman’s Paradise.
It’s surrounded by houses and camps along the 22-mile shoreline, and is the top outdoor leisure draw for the city of New Roads. However, below the surface of the water you will discover that False River is sick and has been for some time.
Once designated a trophy lake for bass in the early 1990s, the lake has been choked by excess silt and sedimentation that accumulated over the span of several decades. The problem became so bad that False River was recognized as a lake of special concern in 1998.
The following year, the Louisiana House of Representatives asked the Louisiana Department of Wildlife and Fisheries (LDWF) and the Louisiana Department of Natural Resources to study the problem and make recommendations to improve the habitat quality of the lake.
This led to years of studies by the U.S. Army Corp of Engineers, numerous state agencies and private groups. Restoration plans were developed and funding sources were identified. During this period the LDWF continued to monitor the decline of the fisheries in False River.
Finally, in 2012, the House created the False River Watershed Council and tasked it with initiating solutions for the waterbody. Though still years away from returning to optimum health, these fixes appear to have False River on the road to recovery, according to LDWF biologist manager Brian Heimann, who oversees LDWF’s involvement with the lake.
“Everything that we’ve dealt with is the result of habitat loss and degradation over several decades,’’ Heimann said. “What we’re doing now with the False River Watershed Council and our agency partnerships is trying to correct some of those habitat loss issues.
“I think, overall, all the folks that are working on the project are optimistic about the future. As far as from a fisheries standpoint, it’s going to take several years before we see measurable gains. The habitat has to improve first. That’s what our focus is, improving the habitat.’’
What Happened to the Habitat?
Once part of the Mississippi River, False River became an oxbow lake in 1722 when the river altered its course east and left a portion of the channel isolated.
More than 240 years later, the U.S. Soil Conservation Service, now the Natural Resource Conservation Service, began development of the Bayou Grosse Tête Watershed Project in 1964. Its intentions were good. The project was aimed at preventing flooding as well as improving drainage and farming conditions in the False River watershed.
The project included 115 miles of channel work, including dredging of existing drainages as well as the creation of two new channels, both of which would increase the load of suspended sediments entering the lake.
The very nature of the project encouraged conversion of woodland and pasture into row crop agriculture, which hastened the increase of sediment into the lake. Since that time, however, much of the watershed has reverted to pasture or woodland.
LDWF biologists, along with the U.S. Fish and Wildlife Service, voiced concerns over possible adverse conditions that would harm the lake should the effort be undertaken.
Nevertheless, the project went forward in 1976 and was completed in 1993. Unfortunately, by that time, excess silt and sedimentation had already started harming the lake’s bottom and in 1997, biologists recorded the lowest amount of aquatic vegetation coverage in 14 years. Subsequently in 1998, LDWF fish sampling indicated that the bass population was in decline.
The excess silt had killed the majority of the submerged vegetation, which is vital to the health of the lake and to the fishery.
“Every year we go out and map aquatic vegetation,’’ Heimann said. “You could see the decline in vegetation each year based on these maps; a reduction in coverage of vegetation that coincides with the introduction of sediment into the lake. When submerged vegetation and water quality declined, so did the fishery.’’
Fixing the Lake
One of the goals of the creation of the False River Watershed Council in 2012 was to supplement the sport fish populations until habitat enhancements could be made.
The Pointe Coupee Police Jury, LDWF and other private donors helped to construct gravel fish spawning areas, to help promote increased fish populations. LDWF has also continued to stock the lake with bass and other fish. Special commercial netting regulations have been implemented to promote commercial harvest of rough fish (carps, gars, etc.), thereby reducing the number of rough fish that contribute to habitat degradation.
“Our stocking continues now and we continue to sample,’’ Heimann said. “We constantly monitor the lake, and assess not only sportfish, but commercial species, aquatic vegetation, and habitat condition as well.’’
In January of 2014, a $2.7 million restoration project was announced that would further restore the lake. The project began in the fall of 2014 when a drawdown was instituted in order to create a 16.5 acre island in the south portion of the lake, also known as the South Flats.
“They used a dredge to build a 16.5 acre ring levee,’’ Heimann explained. “Once the levee was built, they pumped sediment out of the lake bottom into the ring. It’s basically a ring levee that is a bowl and you’re filling it up with sediment. It created several thousand linear feet of edge habitat.’’
A total of 45 acres of lake bottom was dredged to build the island and it created fisheries habitat through the establishment of aquatic vegetation, black willow, cut grass and other native plants, Heimann said.
Plans are in the works to do something similar on the north end of the lake, Heimann said. Instead of creating an island, though, the idea is to pump the dredge material onto land adjacent to the lake that isn’t designated as a wetland.
“We’re hoping to be able to suction dredge and move it to the land,’’ Heimann said. “Right now, this is in the design phase. Hopefully, it will be done in the next year or two.’’
Another important piece of the restoration project is fixing the drainage issues with the major arteries that deliver runoff water into False River, the M-1 and M-2 canals. The False River watershed is made up of more than 34,000 acres. The M-1 Canal, or Discharge Bayou, is the primary canal that stretches 5.15 miles. It delivers water that comes from about 75 percent of the watershed into the South Flats part of the lake. The M-2 Canal, or Patin Dike Slough Canal, delivers the remaining 25 percent of watershed runoff into the northern part of the lake. It is 3.33 miles in length. Both were built as part of the watershed project completed in the early 1990s.
“They’re basically placing big rock weirs and baffles into the canals,’’ Heimann said. “This will reroute the drainage so the water slows down, hits the weir and the sediment falls out behind the weir. Then the water goes through (to the lake) with less sediment.
“The primary aim is to correct the problems with M-1 and M-2 so that they will contain the sediment in those drainage canals instead of releasing it into the lake.’’
The M-1 Canal project was completed in August and the M-2 Canal is expected to wrap up this month.
Another vital piece of the puzzle is the use of drawdowns, Heimann said. The first full drawdown, undertaken in 2016, appears to be paying dividends.
The lake had to be lowered slightly for the island dredging project in 2014. But the first full drawdown came in the fall of 2016 when the lake level was lowered 5.5 feet.
Drawdowns allow sunlight to dry and break down the excess sediments and organic material. This improves spawning habitat and may aid in the regrowth of submerged aquatic vegetation.
“We’ve already seen some benefits from the drawdown,’’ Heimann said. “We measured compaction and consolidation rates of the soil. One of the benefits we hope to achieve with drawdowns is to reduce the amount of organic material in the substrate. We’re compacting the sediments for nesting fish like bass, bream and sac-a-lait. They like a firm substrate on which to spawn. Egg survival is lower when it’s silt. The eggs will suffocate. When it’s firm there is more success.
“We’ve also seen emergent vegetation returning in areas where there was none before the drawdown - in the south end of the lake, and even on the perimeter to some degree. In other areas, we’ve seen cut grass, smartweed, lotus, and alligator weed and other species of aquatic vegetation. We’re hoping for more positive benefits in the future.’’
The increase in submerged vegetation is also good for the fisheries, aquatic habitat and other species that use the lake, Heimann said. It also acts as a nutrient extractor, soaking up excess nutrients and storing it in the vegetation.
“This helps prevent large algae blooms,’’ Heimann said.
False River underwent another drawdown earlier this fall that started shortly after Labor Day. Due to heavy rains, the lake re-filled in October, and the drawdown was terminated as the expected benefits could not have been achieved under those conditions.
“We like to do two or three drawdowns within the first five years (of a project),’’ Heimann said. “Several in rapid succession. After that, you can stagger them out more. The reason we close the gates on Jan. 15 is we don’t want to negatively impact the spring spawn. Also we want the lake at the optimum level for spring and summer recreation users. False River has a big watershed, a 3,000 acre lake with more than 30,000 acres of watershed. With adequate rainfall it should fill up in a short time. Last year, after the gate was closed, the lake was back at normal water level within a week.’’
Heimann said there was some trepidation among the people living along the shores of False River and concerns about what the drawdown would do. Hopefully their fears were allayed some because of LDWF and the False River Watershed Council’s public education campaign. Actually going through the drawdown helped, too, he said, as lake residents saw the benefits.
“Though it’s not scientific, we’re hearing from the fishermen that things are getting better (because of the drawdowns),’’ Heimann said.
One other possible enhancement would be to construct artificial reefs. But that remains in the planning stage for right now.
“The hesitation is where to put them,’’ Heimann said. “You need a relatively flat area. You don’t want the structure to slide off of the target area into deep water. Also, for us, the north and south ends would be ideal but those may be dredged in the future. We wouldn’t want them to get destroyed by a dredge.’’
Though there are many positive signs, the restoration of False River is an ongoing process. There will be a need for more drawdowns, and if funding is available there could be more dredging projects in the future. Also, additional watershed improvements could be needed in the future.
“It’s not X, Y, Z and we’re done,’’ Heimann said. “It’s an evolving, ongoing process.’’
Louisiana State Representative Major Thibaut, D-New Roads, has helped lead the collaborative effort between the state and Pointe Coupee Parish government to return the lake to good health. He believes the project is proceeding in the right direction.
“While many land management improvements have been made along the banks and tributaries over the years by local farmers and property owners, a significant amount of silt makes its way into the lake each year,’’ Thibaut said this spring. “By utilizing better erosion control methods throughout the False River watershed, we take another step in the right direction to making one of Louisiana’s greatest resources all that it can be.’’
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