36' - Lockmasters house and the lower Corps building at the lock and dam begin flooding.
35.5' - LaGrange Road (County Highway 12) is flooded south of LaGrange Lock and Dam.
29.5' - La Grange Lock Road (County Road 1730N) is flooded just north of the Lock and Dam.
28.8' - County Road 500N south of La Grange is closed due to flooding.
24' - Extensive wetland acreage south of La Grange begins flooding.
23' - Adjacent farmland and wetlands begins flooding. Island Road across the river in western Cass County begins flooding.
20.5' - The lock wall is completely overtopped.
16.5' - The earthen part of the dam is overtopped.
15.5' - Normal pool level (429.0 NGVD29).
14' - Dam goes up at this pool level (427.5 NGVD29).
5.6' - At and below this height, barge traffic will need to consider lowering tonnage to avoid grounding.