With all of the rain that we have had in the Kansas City area this year, it’s a good idea to address the water issue with some practical solutions that are long lasting and can handle your design precipitation event.
First thing is to make sure when grading a field to slope the ground in such a way as to channel the water in one direction. Once you have all the water moving in the same direction, next think about how the water will move once it is beyond your field. You may want to talk with your neighbors about what you are planning to do. Consider using a Swale or Ditch to keep the water flowing. Make sure that if you are adding additional impervious surface that you consult an engineer for ways to keep the same flow or less flowing off your field, per the design precipitation event.
It’s a good idea to have enough slope on your swale or ditch. Slow moving water tends to stagnate and create soft swampy areas on your field. If you can get 2% slope, or 2 feet of fall in 100 horizontal feet, that is excellent. The least amount of slope that you would ever want would be 0.5% slope or 6” of fall in 100 horizontal feet. Generally, it is good to keep the water flowing in the natural path that it is currently flowing in, however, engineers sometimes “roll” the slope to keep at least the 0.5% slope on the swales. Contact your local engineer to help you achieve enough slope on your field.
In those areas where there is existing ponding, consider having an engineer design an Infiltration Trench or French Drain. Perhaps the engineer can find a way to release the water without designing one of those Best Management Practices. It is something to ask the engineer, because moving the water is always the better scenario. The Infiltration Trench and French Drains increase the area of storage as well as encourage water “soaking” or infiltrating into the ground, should the soil conditions be right for it.
If the ponding area is large and has been there for some time, speak with your local engineer. It could be that you have a designated wetland on your property and there are special considerations that must be followed when disturbing a wetland. Anything is possible, but the governing authorities such as Army Corps and the Department of Natural Resources must be notified and their guidelines must be met.
Best wishes for keeping the water flowing in your fields! Please feel free to contact Kahn Engineering even if you are out of the Kansas City Area. If you send us an email and describe your situation, we can get you pointed in the right direction for when you talk to your local engineer.