A major milestone of sorts has been reached on a drainage control project for Fondren.
The city of Jackson recently received approval from the U.S. Army Corps of Engineers to widen and clean up a tributary of Eubanks Creek. Meanwhile, contractors were still working to obtain corps approval for another drainage project along Eubanks Creek, and were looking at potentially more effective alternatives for preventing flooding from Belhaven Creek.
The tributary runs from Forest Avenue to Witsell Road in Jackson.
The project will reduce flow going into Eubanks Creek, a major creek that runs through Fondren.
The city is now turning its attention to obtaining easements for the project and bringing on a contractor to make improvements, according to Engineering Manager Charles Williams.
“Hopefully we can begin (obtaining easements) by the first of the year, and then by summer we can start construction,” he said.
Work is expected to run around $1.4 million.
About 30 easements will be needed, affecting homes along Kirkley Drive and Belle Meade Place.
Williams discussed the project at a recent one-percent oversight commission meeting.
The project was identified as one of several drainage improvement projects that would be funded with one-percent infrastructure dollars.
The project will include cleaning the creek, removing vegetation along its banks and adding new rip rap to prevent erosion.
The project originally ran to Northside Drive, but has been scaled back due to costs.
Williams said there are a large number of trees growing in the creek bed. In many cases, the roots aren’t deep enough to hold the trees in the ground as the banks erode.
Fallen trees and other debris from the vegetation causes the creek to back up during heavy storms.
While that project could move forward by the summer, the city was still awaiting corps approval on one that would increase capacity along Eubanks Creek from North State Street to Eagle Avenue.
“Stantec is working to get the corps permit now,” Williams said.
The second project will call for slightly widening the creek, as well as removing vegetation and adding rip rap.
“We’ll widen the channel as much as we can to provide some relief,” Williams said.
The North State to Eagle work is expected to run around $2 million and require 27 easements along Choctaw Road and Eagle.
Design work was expected to wrap up this month.
Both projects are expected to increase drainage capacity, so the creeks can handle 10 to 15-year storms.
A 10-year storm is a storm that has a chance of occurring 10 percent each year during a 10-year period, while a 15-year storm has a roughly 6.5 percent chance of occurring annually in a 15-year period.
As for Belhaven Creek, the city is considering other options for improving drainage.
“We’re looking at options that could be better than the current one,” Williams said.
Williams told the commission that engineers were looking at new data, but declined to provide additional details at press time.
In 2016, the city brought on Southern Consultants to draw up plans to address flooding along the creek.
In July, Southern proposed replacing box culverts under Piedmont and St. Mary streets, and rechannelling the creek there, building concrete walls along the creek banks between Piedmont and St. Ann Street and adding rip rap from Laurel Street to Piedmont.
Rip rap are large gray stones often put along banks and shorelines to reduce erosion.
Southern estimated that the work would reduce flooding from a 25-year storm by four feet at St. Mary, between two and three feet at St. Ann, a little more than a foot at Lyncrest Drive and half a foot at Linden Place.
A 25-year storm has a four-percent chance of occurring once a year during a 25-year period, according to the United States Geological Survey (USGS).
The upgrades would cost $2 million and alleviate nearly all of the flooding that would occur in the event of a storm similar to the one that inundated the area in July.
On July 10, a major storm ripped through Fondren and Belhaven, causing flooding along several neighborhood streets just south of Riverside Drive.
That storm dropped between 2.5 and five inches of rain in less than an hour, according to National Weather Service (NWS) data.
According to the agency’s Flowood office, the creek didn’t flood just because of the rain, but because of the precipitation coupled with heavy runoff in the Belhaven Drainage Creek Basin.
“There was a pretty hefty event over that area,” NWS Hydrologist Marty Pope said. “The problem was the storm’s intensity and the fact that it didn’t fall over grassy areas.”
The Belhaven drainage basin runs basically from Glenway Drive and Lakeland Drive in the north to Pinehurst Street in the south. East to west, it stretches from Museum Boulevard to Veterans Memorial Stadium and Millsaps College.
It takes in the University of Mississippi Medical Center, the G.V. (Sonny) Montgomery VA Medical Center, Belhaven University and other development.
NWS statistics show more than 99 percent of the area is developed, while 41.58 percent of the area is impervious, such as parking lots, buildings and roofs, Pope explained.
Impervious areas do not soak up rain water, like natural ground, meaning the runoff has to go somewhere. That runoff quickly filled Belhaven Creek, leading to the flash flooding.
At Riverside, the creek rose from 3.16 feet to more than 13 feet between just before 7 p.m. and 7:30, and at Laurel Street, the creek went from 2.8 feet to 10.37 feet between 7 and 7:45, he said. The storm itself lasted about an hour.
While 2.5 inches fell in the Laurel Street area, Pope believes between three and five inches fell north of Riverside, which helped lead to the flooding.
Southern is also working with the city on the alternative plans, Williams said.
