The great flood of May 4, 2015 was big enough to have citizens paddling down the street in kayaks and inflatable pool toys. As much fun as that was, floods can cause some serious damage.
For starters, the excessive rain Manhattan is experiencing recently can cause harvest delays and declines, amongst other problems, with local agriculture.
“The first (problem) is delays in planting because the fields are too wet for people to get into them,” Mary Knapp, service climatologist in the department agronomy, said. “The second (problem) that comes into play is that if the crops had been in the ground, then they are in standing water, which limits the development of the root system and makes them more vulnerable to various diseases. The final problem is that there’s been difficulty applying some of the pesticides they might normally do, both to control weeds and to control pests.”
According to her, the impact at the end of the crop season depends on how the weather continues throughout the season.
“If it turns off dry too quickly, even though technically we are above normal for the moisture, the roots can’t grow fast enough to keep up with the declining water channels,” Knapp said. “So you can get drought stress even though we may be above normal for the monthly rainfall. If it continues with the wet pattern, with timely rains, we could have some fairly good productions.”
If a drought scare like this occurs, the yields for affected farms could lower and, in turn, impact their profit. According to Brian McNulty, operations project manager at the U.S. Army Corps of Engineers at Tuttle Creek Lake, the lakes run off system has affects on where the agricultural damage is.
“Downstream we have not released any water in excess of the rivers channel capacity, so it’s improved agricultural conditions downstream,” McNulty said.
According to McNulty, some of the water storage happening upstream has caused slightly worse conditions there than in downstream areas and “some of the areas surrounding the lake upstream of the dam have flooded and caused some agricultural damage.”
Because of this and other types of damages, Manhattan has to have systems and plans in place in order to control flooding around the city.
“Manhattan was founded between two major rivers and a large creek, so flooding is always an issue,” Chad Bunger, senior planner in the Manhattan Community Development Department, said. “It’s just a matter of if the conditions are right.”
Some of the conditions and factors, according to Bunger, include soil moisture and rainfall. One of the ways that the city helps to control these are by using systems like storm drain systems for water run off.
“Our Public Works Department has quite a bit of infrastructure in place to control (flooding),” Bunger said. “Sometimes the rains just are excessive or variables happen that are beyond our control and flooding happens, but we’ve got a lot of underground and above ground infrastructures dedicated to dealing with storm water run off.”
There are engineers who work to discover the most effective places for things like storm drains to be located.
“Basically, it’s engineering calculations of where the water runs off, how much water runs off, elevations of where it makes sense to put storm drains,” Bunger said.
This is coupled with another flood management system, the Tuttle Creek Dam. Workers at the U.S. Army Corps of Engineers at Tuttle Creek help to monitor the water level situations and, in turn, help to determine where the water goes.
“When we have heavy rains, we collect and store that excess flood control water in our lake until down stream flow conditions are low enough so that we can make releases without increasing the flooding downstream,” McNulty said.
One other mechanism that the city has recently begun to use for flood preparation is the Internet. Within the last two years, a page on the city of Manhattan website has been created to help prepare and inform citizens about flood risks and preparations. The website began because of newly mapped flood planes for the city.
“Where it started was last year and into 2013, we got new flood maps for Riley County and Pottawatomie County and those new flood maps were going to affect a lot of properties,” Bunger said.
This means that some properties were being removed from a flood plane, but that others were being added. This can be important information for those in the changing areas as it affects things like flood insurance and also makes those property owners aware of the flood risk, according to Bunger.
The current rain patterns, while potentially damaging, could fall back into a more regular pattern though and could give farmers, citizens and those working flood and water based jobs, a break.