Floodplain administration: Tusayan enters agreement with county flood control district
Town ordered to restore Ten X development area to original water storage capacity, install flood control measures
TUSAYAN, Ariz. — The town of Tusayan voted to enter an agreement with the Coconino County Flood Control District Feb. 4 to begin the process of obtaining a floodplain permit. The plan was approved by the Coconino County Board of Supervisors at its Jan. 29 meeting.
The agreement in the form of a court order lays out several key requirements for the town to complete in order to obtain the permit, and states that insufficient data was provided to the district to properly evaluate the effect of the development work within the floodplain, and that it could pose a potential safety risk.
The agreement requires the town to design flood mitigation measures to restore water conveyance and storage that existed on the property prior to construction work completed at the site. The proposed design must include a map of the work areas, channel and basin details, typical details and hydrologic and hydraulic calculations of potential floods. That information will be provided from studies commissioned by the town, and should be available in the coming weeks, according to Tusayan Mayor Craig Sanderson.
Sanderson said the town will comply with all the requirements set forth by the agreement, although he sees them as temporary measures that will hopefully be replaced by more agreeable permanent mitigation measures in the future.
Sanderson said the agreement right now is to restore the development property to the condition it was in prior to construction activity until the town either assumes its own floodplain administration duties or receives a permit from the flood control district. At that time, engineers will be able to design permanent measures based on the studies that coordinates with the already-laid-out subdivision.
One example, Sanderson said, is a stock tank that was removed when the property was graded and a hillside removed. That altered the storm water storage capacity of the area.
“If the flood plain study comes back and says we don’t need those, then they go away,” he said. “Now maybe the study comes back and says we really need to have something, they stay, (and the engineers can design something that fits within the subdivision).”
Sanderson said the development’s solar panels are planned for that particular area, and that the town would need to spend a little more money to raise them with poles.
Another sticking point is the entrance road, which altered free-flowing water in the area. Sanderson said the town had purchased and planned to use culverts, but without the results of the study, the county is concerned that they may not be able to handle enough water flow. Sanderson said in the future, the town still plans to use a culvert system under the raised entry road, but for now will use a breach — a deep dip the the road down to the water flow level — as suggested by the county engineers.
The second step of the process will come later, Sanderson said, but the construction can continue under either the town’s own administration or via the permit issued by the county when compliance is met.
“If the county retains floodplain (after a referendum vote in May), then we’ll get a permit from the county … that will describe in detail what we can do and need to do in the development itself,” Sanderson said.