## Facts

- Landowners and tenants owned or rented property along Wakenda Creek near State Route 10 and U.S. Route 65 in Carrollton County, Missouri.
- Before the highway project, Wakenda Creek regularly overflowed after heavy rains; the floodwaters crossed Route 10, pooled, and then moved across portions of plaintiffs’ land before returning to the creek downstream.
- These pre-project floods were brief and had not reached or damaged plaintiffs’ buildings.
- The Missouri Highway & Transportation Commission (MHTC) condemned parts of plaintiffs’ property to build a U.S. Route 65 bypass.
- MHTC elevated the bypass and installed a culvert intended to carry water flow.
- After construction, the raised roadway and culvert configuration impounded water during heavy rains and altered flooding patterns.
- Plaintiffs’ buildings and improvements, previously unaffected, were flooded; plaintiffs alleged the bypass and undersized culvert caused the increased flooding and property damage.

## Issues

1. Whether Missouri should continue applying the modified common enemy doctrine to surface-water runoff or instead apply a reasonable-use rule.
2. Whether, under the proper surface-water doctrine and the standard for judgment notwithstanding the verdict (JNOV), the evidence supported the jury’s finding of a compensable taking or damaging (inverse condemnation) from flooding caused by the highway project.

## Decision

- The Supreme Court of Missouri (en banc) abandoned the modified common enemy doctrine for surface-water runoff and adopted a reasonable-use doctrine.
- The Court reversed the trial court’s grant of JNOV for MHTC.
- The Court held that, viewing the evidence in the light most favorable to the verdict, plaintiffs made a submissible case that MHTC’s design unreasonably altered surface-water flow and caused substantial damage.
- The case was remanded for further proceedings consistent with the reasonable-use rule.

## Legal Principles

- Surface-water disputes in Missouri are governed by a reasonable-use doctrine rather than the modified common enemy doctrine.
- A landowner, including a public entity, may make reasonable improvements affecting surface-water drainage, but may be liable when changes to surface-water flow are unreasonable and cause substantial injury to others.
- In inverse condemnation, government action that unreasonably causes recurring or significantly increased flooding that substantially impairs use or value of private property can constitute property being “taken or damaged,” requiring compensation.
- JNOV tests whether the plaintiff made a submissible case; appellate review considers the evidence and reasonable inferences most favorable to the jury’s verdict and disregards contrary evidence.

## Conclusion

Missouri replaced the modified common enemy doctrine with a reasonable-use standard for surface-water runoff and held that landowners could pursue inverse-condemnation recovery where a highway bypass and culvert design unreasonably altered drainage and newly flooded previously unaffected structures, making JNOV improper.


Heins Implement Co. v. Mo. Highway & Transp. Comm'n, 859 S.W.2d 681 (Mo. 1993)