The most severe flooding during the April 1989 flood in the Red River of the North Basin in North Dakota and Minnesota occurred in the Wahpeton-Breckenridge area. Flood stage on April 5, 1989, was the highest stage that has been reported in almost 100 years. The 1989 peak flow was not as large as that of the 1969 flood, which had the largest peak flow since the Wahpeton gage was installed in 1942. The 1989 peak stage, however, was more than 1 foot higher than during the 1969 flood because of backwater from ice. Cooler weather subsequent to the peak at Wahpeton slowed the snowmelt and allowed the peak to attenuate as it moved downstream; thus, the severity of flooding in the Fargo-Moorhead area and in areas farther downstream was reduced. Advance flood warning allowed communities downstream from the Wahpeton-Breckenridge area to prepare for the flood and was instrumental in reducing flood damage. Aerial photographs were used to delineate the extent of the April 1989 flood in the Wahpeton-Breckenridge and the Fargo-Moorhead areas on topographic maps. The aerial photographs of the Wahpeton-Breckenridge area were taken during the flood peak on April 5 and those of the Fargo-Moorhead area were taken during the flood peak on April 9.
