Fort Smith directors talk drainage issues for major city watershed

FORT SMITH -- The city is considering spending millions of dollars buying property as a way to address flooding problems.

Stan Snodgrass, director of the Engineering Department, provided city Board directors an overview of drainage issues in the May Branch watershed earlier this month, as well as efforts by the city to address them spanning multiple decades.

The board discussed spending about $12 million to buy about 230 properties that have flooded in the watershed.

The idea is to convert the properties into parks or ballfields, which could hold water better than a land with a structure, Snodgrass said.

Jarred Rego, director from Ward 1, said the issues Snodgrass described struck him as a "textbook example" of why residents become frustrated.

"You're talking about three decades' worth of recognition of the problem, three decades' worth of money being spent to the tune of hundreds of thousands of dollars hopefully in service of helping the problem, hundreds of homes impacted, thousands of people," Rego said.

Snodgrass in a memo defined a watershed -- also known as a drainage basin -- as an area of land "that drains all the rainfall to a common outlet or discharge point."

The May Branch watershed is Fort Smith's fourth-largest drainage basin at about 4,000 acres, or 6.3 square miles, Snodgrass said. Its southern limit extends to Southside High School, with water that drains on the north part of the school generally running about 5 miles and discharging at North P Street before going into the Arkansas River. Water flows into an underground storm sewer system at Park Avenue, which extends nearly 3 miles to the river.

The system was built in 1910 as a combined sanitary and storm sewer system, according to Snodgrass. The system varies in size, with pipes ranging from about 7 feet in diameter at Park Avenue, 9 feet along North O Street, 11 feet at Midland Boulevard and 12 feet at the outfall at the Arkansas River.

Feasibility study

Snodgrass said the city asked the U.S. Army Corps of Engineers to study the flooding problems along the May Branch area in January 1991. A Reconnaissance Report issued the following year recommended proceeding to a joint corps-city feasibility study for a flood reduction project.

A feasibility study and conceptual design agreement between the two entities was approved in 1998. The estimated cost was $1.4 million, with the city paying $700,000 of that amount.

The study proprosed building a large open drainage channel extending 2.75 miles from Park Avenue to the Arkansas River. The channel would follow a path similar to the storm drain already in place.

However, Snodgrass said a project must have a "benefit to cost ratio" greater than 1 to be eligible for federal funding. This ratio compares the cost of the benefits, such as flood damage reduction costs, to the overall cost of the drainage improvement project, the route for which is divided into six segments called reaches.

The total benefit to cost ratio for the first four reaches, which collectively span from the Arkansas River to Grand Avenue, was 1.09. Federal funds cannot be used for Reaches 5 and 6, which go from Grand to Park avenues, because they fall short of a minimum flow requirement.

Cost escalates

The May Branch Drainage Project was federally authorized in November 2007 at $31 million, Snodgrass said. However, federal funding was unavailable. The city executed a design agreement with the Corps of Engineers in 2008, contributing $554,000 for project design at that time. It provided another $500,000 in 2013 in the wake of no federal funding in the intervening years.

Snodgrass said the Corps of Engineers informed the city in 2016 that it estimated an overall cost of about $32 million to construct just Reach 1. Extrapolating this to the total project cost led the Corps to estimate a revised overall cost of about $65 million.

That would kick the benefit-to-cost ratio below 1, meaning federal funding is no longer an option, Snodgrass said.

Snodgrass said the city retained the Little Rock-based firm FTN Associates in January 2017 to revisit the Corps' channel design and look for possible cost reductions, as well as consider alternative methods to reduce flooding. They found the most cost-effective option would be to buy properties.

Snodgrass said a flooded residence buyout program was approved by the city in 2019 at an annual amount of $250,000. This is a voluntary program through which the city could purchase residential properties that have experienced structure flooding if the cost of the residence/property is less than the cost of public drainage improvements to reduce the flooding. No properties in the May Branch area have been purchased to date.

Snodgrass said buying out properties affected by flooding in the May Branch watershed would be a voluntary program. City Director Lavon Morton suggested trying to do a survey of the homes there that flood frequently and discussing buyouts with the owners.

City Administrator Carl Geffken said the city is also trying to find a way to meet the threshold for the benefit-to-cost ratio to open the project up for funding. One possibility is setting money aside to help bring down the cost of the project.

"We're looking for ways, including grants, that we can bring this together for the city and start to chip away at our flooding issue," Geffken said.