Rock Valley, Iowa — With all this snow and the forecast for this spring, Rock Valley city officials are again concerned about flooding.
Last week, the Rock Valley Flood Committee met with Sioux County Emergency Management Director Nate Huizenga to discuss possible flooding this spring. Mayor Kevin Van Otterloo called this meeting after the National Weather Service issued their Flood Outlook for March through May 2019 Report. This report says that probabilities for minor and moderate flooding are generally above normal for all areas, with normal to above normal chances for major flooding. The areas with the greatest threat for major flooding include the Rock River below Luverne, Minnesota.
They go on to say that additional future rain/snow will be the biggest factor in how bad the flooding gets this spring. They say that due to the wet conditions last fall, the soils were very wet heading into freeze-up, and river levels have been running at higher than normal levels this winter. Rock Valley officials say the rainfall event around Christmas added additional moisture to the system. Some of this rain ran off through the rivers into early January, but much of it is still being stored as frozen moisture in the upper levels of the soils. One of the biggest question marks at this time is how saturated the frozen soils still are and how much of the water from the snowmelt will be able to be absorbed into the soils. Also, the snowpack has increased significantly over the last month. The water equivalent of the snowpack is generally 1 to 3 inches, with isolated amounts of 3 to 4 inches, according to the National Weather Service. They say the probabilities referenced in this outlook are calculated by taking the current conditions of the rivers, soils, and snowpack, and then running the hydrologic models using historically observed temperature and precipitation for at least 30 years.
Rock Valley officials tell us that the Flood Committee had a lengthy discussion on available flood fighting resources and what needs to be purchased before a flood event. Emergency manager Huizenga said that the County has purchased numerous pumps that will be available for any possible flooding. The City talked about land the City is acquiring so permanent berms may be constructed in 2019.
The City and County tell us they will continue to monitor the weather conditions and they will continue to update the flood forecast on the City’s Facebook page.
