ORANGE PARK – Preparing for the water of a 100-year event like 2017’s Hurricane Irma is cost-prohibitive, according to a study commissioned by the city council.

The Orange Park Town Council commissioned Jacksonville-based engineering agency Jones-Edmunds to create a flow model to understand how the town could prevent the damage created by Irma. They learned it’s not economically feasible.

“Planning for the 100- or five-year events would be cost prohibitive,” Jones-Edmunds Vice President and Managing Director Brian Icerman said. “Planning for stormwater levels of that size is beyond the scope and scale of the town.”

A 100-year event is based on probability, not a timeframe. A 100-year event means there’s a 1% chance of a crippling storm like Irma every year.

Icerman said Orange Park should focus on conveyance for 10-year events and storage for 25-year events.

In the realm of events and their associated year amount, the numbers represent how often an event might happen. Irma was classified as a 100-year event.

Conveyance in stormwater management deals with a town’s ability deal with flood waters. Storage in stormwater management is the use of manmade and natural features such as aquifers to store otherwise overwhelming amounts of stormwater.

“We could argue for days whether or not a creek or Dudley Branch is storage or conveyance, but for the sake of argument, let’s call anything localized 10-year and the major ones 25 because the town doesn’t really have any major storage system as in a reservoir,” Icerman said. “The way the town comp plan reads, the town is not obligated to protect beyond that. That doesn’t mean you shouldn’t choose to – it just means that as far as what you have promised in the comp plan is to protect up to the 25-year event.”

Icerman said as the town continues its work in improving stormwater management and maintenance, the town will soon hit a breakpoint in the cost-benefit curve. He doesn’t recommend the town proceed beyond a 25-year event.

“So, you’ve got this tool (the flow model) that allows you to do what-if scenarios,” Icerman said. “The next steps are to look at these improvements, prioritize them, find out what’s the right combination of (cost and benefit) and eventually, you’ll have to put everything together in a capital plan.”

Icerman said the perks of the flow model is that with all future stormwater projects, the town can utilize the what-if scenarios to determine what could happen in different areas of town.

The town is still waiting to receive FEMA money for hurricanes Matthew and Irma, and it’s pursued grants to help pay the cost of stormwater.