City and county officials believe a new flood-response plan, better forecasting gauges and a countywide emergency notification system will help protect the public the next time floodwaters rise in the community.
The flood response and evacuation plan has been tested twice in large-scale City Hall exercises, where officials practiced the decision-making processes outlined in the plan.
The flood plan exists in three- to four-inch-thick binders, packed with flow charts, phone trees and flood maps, which have been distributed among decision makers in city and county government. It clearly outlines who is responsible for decisions and when various components of an emergency response will be called into play.
For example, it outlines who decides when to commandeer school buses to transport victims, identifies safe routes to transport those residents and explains where the safe gathering places are in each area of the community.
Where residents in the path of the 2008 flood had virtually no notice of the onrushing danger, the new plan and equipment will allow up to six hours’ notice for a rising Haw Creek — time enough to safely leave the area with valuables and pets, Mayor Kristen Brown said.
“The advance warning we get is based on stream size, so on some of the larger ones we could get a day to two days, and on some of the smaller ones like Haw Creek, which is our most problematic one, we could get hours,” Brown said.
“We can close roads accordingly. We can evacuate neighborhoods accordingly.”
The plan takes advantage of new storm gauges on Haw Creek, installed in 2010, said Jeff Bergman, the city/county planning director. The better information will be paired with the county emergency notification system, which allows emergency officials to call tens of thousands of phones with warning information in a matter of minutes.
During a potential flood in the city, the plan will be brought into play by the incident coordinators, Dennis Moats, director of Bartholomew County Emergency Operations Center, and Columbus Fire Chief Dave Allmon.
“Our job as the coordinators is to carefully monitor the situation and then, if we feel we are really going to get clobbered with flooding, pull together the key players,” Moats said.
As it becomes apparent a potential incident is turning into a real flood, a unified commander will be designated to begin the process of mobilizing agencies and organizations that are needed to respond. Depending on the level of the flood, that might involve city police, the sheriff’s department, schools or agencies such as the Red Cross, Moats said.
The main decision-making process in the plan breaks down floods into one of four categories for each river and stream in the city, ranging from a mere threat to major flooding. The emergency officials then work through a series of steps, determining the expected level of the flood threat, communicating and notifying the necessary organizations and agencies, and then orchestrating the expected actions those entities should take.
Christopher B. Burke Engineering LLC, which created the flood-response plan, has prepared new flood maps for the city, which officials believe will more accurately estimate how deep the water will be in different parts of the community at various flood stages on each waterway. Those maps are being incorporated into the software in the dispatch stations at the county emergency operations center.
The new flood maps look at four levels of flooding: 10-, 50-, 100- and 500-year floods.
“Based on the gauges we have upstream on all of our streams and rivers ... we know when and where we are going to flood and by how much,” Brown said.
Siavash E. Beik, a civil engineer with the engineering firm, said other flood maps produced by the Indiana Department of Natural Resources or the Federal Emergency Management Agency are regulatory maps without the depth and intensity information that the new maps contain.
“Every time the (flood) reaches a certain elevation on the stream, you have a reference to see how wide this is going to flood, how deep it is going to flood,” Beik said.
The emergency-notification system will take advantage of the new maps, allowing the calls to be tailored to specific areas with targeted information as floodwaters rise. For example, residents of a specific neighborhood could be told of their recommended evacuation route and where they should gather to be rescued by emergency workers.
The notifications system also will be used to alert emergency officials en masse to various stages of the response and allow for conference calls among coordinators.
The last major exercise of the flood plan was Feb. 12, when officials from the city, county, school district and other agencies gathered around a large rectangle of conference tables at City Hall to handle a scenario planned by representatives from the engineering firm. The officials simulated the phone calls and assistance that would take place if Haw Creek again rose to flood level, fueled by heavy rain to the north. When the exercise kicked off, emergency officials were asked to deal with a creek that progressed from a simple threat at 9 feet deep, to raging waters as it passed 15 feet.
Moats said that the various emergency response agencies in the community are being encouraged to adopt the same basic response structures for any major incident and even minor ones. That helps all agencies get in the practice of using the process, he said.
The total project cost for the flood-response plan, assistance with new flood regulations and development of flood mitigation projects was $176,400, Bergman said. The fee is being paid through a combination of a $53,000 federal disaster-relief grant made to the city after the 2008 flood, $118,400 in economic development income tax funds and $5,000 from the planning department professional services fund.
Bergman said he expected the last portion of the project — the analysis of possible mitigation projects — to conclude in July.