Water Resources

In response to a congressional request, GAO reviewed the Corps of Engineers' efforts to deal with the flooding that occurred in September and October of 1986 in northeastern Oklahoma to determine: (1) whether the Corps released water from its reservoirs in accordance with its operating procedures; (2) whether a modification to the Arkansas River Basin Operating Plan adversely affected the flooding; (3) the Corps' weather and flooding forecasting responsibilities; (4) problems with river gauges; (5) how the Corps communicated water release information to state and local entities; and (6) how the Corps conducted post-flood evaluations.

GAO found that: (1) the Corps followed its operating procedures for releasing floodwaters from the reservoirs; (2) a modification to the operating plan did not adversely affect the flooding, since it was not in effect; (3) the Corps' prediction of inflow to Keystone Reservoir was 53 percent below the actual amount; (4) the Corps based its decision to release water from the reservoir on the National Weather Service's forecast, which was close to the actual amount; (5) many river gauges malfunctioned or were damaged during the flooding, but this had a minimal effect, since the Corps took manual measurements; (6) the flooding forecast for Tulsa did not materialize because the released water deepened the channel, which was then able to hold more water than usual; (7) flooding in one town occurred later than predicted because the released water spilled over the river banks and spread out over the land instead of flowing directly to the town; (8) the Corps revised its procedures for notifying state and local governments of impending floods; and (9) the Corps' post-flood evaluation report identified needed corrective actions in engineering, coordination, and personnel matters.