HOT SPRINGS -- The failed drainage system under the strip mall parking lot at 3539 Central Ave. poses too urgent a traffic hazard for the city to wait for the state or property owner to take action, the city told the Hot Springs Board of Directors earlier this week.
The public works department asked the board to authorize a $285,000 transfer from the city's stormwater fund to repair the two collapsed 42-inch diameter drainage pipes under the parking lot. The transfer to the stormwater drainage improvement account, the awarding of contracts to Coakley Construction Co. to repair the pipes and Scurlock Industries for a junction box and culvert materials are on the consent agenda of the board's Tuesday night business meeting.
According to emails the city provided in response to a records request, the stormwater department inspected the drainage pipes in July. The public works department said the investigation revealed the pipes were constricted to 10% of their original width, causing stormwater that enters from grate inlets on Central Avenue to back up onto the state highway during heavy rainstorms.
"We've had multiple high water and swift water rescues through our fire department at this particular location," City Manager Bill Burrough told the board. "If we get 2 inches of rain in an hour, 2 inches of rain in two hours, that storm system is failing and can't accept that."
Burrough told the board the pipes, which are 15 feet underground, were probably installed in the 1990s. The property was undeveloped at that time, and no stormwater regulations were in place.
"We certainly would not allow that type of pipe to be used today," Burrough told the board. "It's not rated for the kind of weight that's on there. But that is not anything our planning department would've been able to foresee or know prior to approving the permits for the additional structure that was built there."
Property owner Tai Pham has said the city damaged the pipes when its utility contractor attempted to locate the 24-inch wastewater gravity main between the parking lot and sidewalk in 2013. He said the excavation ultimately caused part of his parking lot to collapse. The inability to access the sewer main required the strip mall's wastewater service line to be connected to the 6-inch gravity main under Mangum Street instead of the larger Central Avenue main.
A September 2013 work order the city provided in response to a records request indicated the depth of the Central Avenue sewer main prevented the connection of the service line. The city said last month that it had verified the excavation work didn't occur near the storm pipes but that it was willing to contribute to repair costs.
The public works department told the board earlier this week that Pham spent $11,000 on the investigation that revealed the cause of the sinkhole in his parking lot.
"So he has spent some money on the project," Public Works Director Denny McPhate told the board. "He didn't do anything to fix it, but it did allow us to partially understand what was going on with the pavement."
The city asked the Arkansas Department of Transportation to help with the repairs, as the pipes, in addition to carrying stormwater from several businesses to the north and the east side of CHI St. Vincent Hot Springs, receive stormwater from the state highway. The transportation department said it's prohibited from spending money on infrastructure located on private property.
"This is a problem that is affecting not only this property owner, but also all people who try to traverse 7 south and needs to be connected and maintained with the city's stormwater system," City Attorney Brian Albright told the board. "We think ArDOT should participate in this. They declined, and, quite frankly, we don't have time to argue with them."
The city's public works code allows it to assume responsibility for drainage systems on private property if they have a "significant and consistent impact" on public streets and lands.
"This line will be placed in an easement that must be granted to the city," Albright told the board. "This line will become an asset of the city and part of the stormwater utility system that we charge fees to the property owner to implement and maintain."
In 2016, the city went from charging a flat commercial stormwater fee of $6 a month to one indexed to square footage of concrete, charging commercial accounts with large parking lots the highest rates. According to the city code, businesses with 250,000 square feet or more of concrete are charged $450 a month. Those with fewer than 10,000 square feet are charged $12 a month. Residential property owners are charged a monthly fee of $4.25.
According to the city's GIS map, the pipes run along the south side of the Burger King parking lot at 3545 Central Ave. after exiting the strip mall property. Their outfall is an unnamed tributary of Hot Springs Creek.
The Clean Water Act requires municipal storm sewer systems that discharge stormwater to be permitted by the Environmental Protection Agency. Hot Springs' stormwater is conveyed untreated into lakes Hamilton and Catherine.