http://www.tulsaworld.com/news/local/planned-development-along-arkansas-river-would-worsen-inevitable-flooding-says/article_ac8a853a-d062-5bbd-84ca-19b67d690d74.html#.Unb1bV-wyL0.emailPlanned development along Arkansas River would worsen inevitable flooding, says ex-official Charles Hardt is worried. The city's former Public Works director is afraid those responsible for planning development along — and inside — the Arkansas River haven't taken into account the inevitability of a major storm upstream from the Keystone Dam and the flooding it would produce. "It's not a matter of if, it's when," Hardt said. The city in the 1970s and 1980s created a world-class flood-mitigation system that has been extremely effective along creeks and Arkansas River tributaries. But applying that same standard to the Arkansas River itself won't do, Hardt said.
"They were basically analyzing for the 100-year (flood) event," he said. "I am saying the 100-year event is not the measure you need to focus on the river." The 100-year-event standard means there is a 1 percent chance of flooding in any given year, or a 67 percent chance of flooding every 100 years. It is used to formulate building standards along the river, and that is where things get more complicated — and potentially more dangerous, Hardt said.
"We are talking about adding more things to the river banks — and potentially in the river — that could make the flooding worse and create the potential for a lot more loss of life and more property damages," he said. Hardt said development in and along the river can act as a "plug" that impedes the natural flow of the river — a flow that in times of heavy rainfall scours the river's bottom and banks to increase the river's capacity.
"You're encouraging development that is not compatible with the river's function, and that is to carry the water from upstream to downstream," he said.
Two major projects are to begin construction soon along the Arkansas River — A Gathering Place for Tulsa park and the River Spirit Casino expansion. Both are betting on the construction of low-water dams in the river to provide a steady stream of water. City leaders, meanwhile, have recently expressed a renewed commitment to constructing a dam in the river after getting a firsthand look at riverfront development in Pittsburgh, Pa., during a Tulsa Regional Chamber tour of the city.
Hardt's advice to them: "Visit with the people who most understand river dynamics, river hydrology and river behavior. And I would argue, to my knowledge, that is the U.S. Army Corps of Engineers." Kirby Crowe, with Program Management Group — which has done extensive work on the proposed Arkansas River dams — says that's already happened. The Arkansas River Master Plan, which envisions a series of dams in the river, has the Corps logo on it, Crowe said.
"They did this," he said of the plan. "Their primary mission is flood-risk reduction. They would not participate if it was adding additional risk." He noted that the dams are being designed to ensure that they do not cause a rise in water levels, either upstream or downstream. "The river doesn't know they're there," Crowe said.
Hardt's not just worried about the dams that might be built in the river. He's concerned about one that already exists — Keystone Dam, and he would like to see a major push to study and repair Corps infrastructure projects. "Its effectiveness and the maintenance of it and what its capabilities are needs to be well understood before we put other things downstream from it — other things meaning low-water dams, development along the river," Hardt said.
Harold Tohlen, the city's floodplain administrator, said the city's policy for developing along the river is fairly simple: Structures constructed along the river cannot increase the runoff on the property. When a new structure does create more runoff, detention ponds must be constructed to hold that runoff. At the same time, any structure built into the river must be done without creating a rise in water levels, either upstream or downstream.
Tohlen acknowledged that even controlled releases from Keystone Dam could create flooding downstream — as it did in Tulsa in 1986 — but said he feels comfortable with the city's 100-year standard. The city's approach is based on the "reasonableness of the frequency of (flooding) occurring," Tohlen said. "The city assumes for risk allowing development above the 100-year standard, that that is a reasonable risk to allow people."
Hardt, for his part, would like to see more open-space development — like the Gathering Place — because that type of development doesn't impede the flow of water. Hardt served as the city's Public Works director from 1990 to 2011. So he knows some people will question why he didn't address the flooding issue when he was on the job. And he can't blame them.
"I could be criticized — and I should be criticized — for not having done that," he said. "But we saw no political will at that point."
