Following the trend in other states, Missouri recently adopted the comparative reasonableness rule for cases involving the diversion of surface water and groundwater. The rule of reasonableness allows a landowner to make reasonable use of the land even though water drainage and flow is altered, as long as the use does not cause unreasonable harm. Missouri’s change to the reasonableness rule from the common-enemy doctrine has yielded favorable results for plaintiffs seeking damages for improper water disposal, but the rule’s initial adoption has left courts with wide latitude in how it should be interpreted. In the last decade, courts have continually expanded the rule of reasonable use in regard to water drainage and disposal, but have not had the opportunity to address reasonable use as it pertains to floodwater, levees, and major flood-protection facilities. The Missouri Court of Appeals for the Western District of Missouri had the opportunity to clarify these issues in Robinson v. Missouri State Highway & Transportation Commission, and it held that the rule of reasonableness apples retroactively to all flood-control measures, whether or not the flood-control method succeeded the rule’s adoption.
Blake J. Pryor,
In the Wake of Heins: Break Out Your Rulers Missouri It's Time to Measure Your Levees,
66 Mo. L. Rev.
Available at: https://scholarship.law.missouri.edu/mlr/vol66/iss2/7