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EXECUTIVE SI:1~vIMARY This report documents the Apri129, 1999 flood event, past flood history, and flood management system performance within the Arkansas River watershed, including Fountain Creek, which enters the Arkansas River at Pueblo, and Monument Creek, which enters Fountain Creek from the north just east of Manitou Springs. The report also addresses defi:ciencies and makes recommendations for improvements. The flood of Apri129, 1999 on the Arkansas River had an estimated peak dischazge of 28,000 cubic feet per second (c.f.s.) at Las Arumas which equates to about a 20 to 30-year event. Tributary flows combined to create a~iver stage of record on the Ark~nsas River at the Avondale gauge on May 1, 1999. This peak wexit on to crest in La Junta on Ma.y 3, 1999 causing extensive flooding and requiring the evacuation of many residents. Flooding in. La Junta occurred when local levees were overtopped and eventually breached by the flow on the Arkansas River. Fortunately, local drainage azeas south of La Junta did not experience heavy rainfall and contributed little to the flooding. The heaviest rainfall occurred in El Paso County within the Monument Creek watershed and the City of Colorado Springs. This runof~ contributed heavidy to the flood damage along Fountain ~ Creek. The estimated peak dischazge along Fountain Creek was 20,1 ~0 c.f.s. at Fountain, which equates to about a 10-year event. Nevertheless, the volume of flow o~1 Fountain Creek caused more erosion damage than any previously recorded flood. Flood dam.ages were also high in Manitou Springs where the channel capacity is extremely restricted by encroaching development. The total damage caused by ~the regior.ial flooding over the four counti.es of El Paso, Pueblo, Otero and Bent counties was in exces:~ of $61 million. Corps of Engi~aeers projects in the area prevenfed in excess of $57 million in damages. On May 17, 1999, th~; President signed DR#1276 declaring the ten counties o;FOterq Ba~t, El Paso, Larimer, Pueblo, Las Animas, Crowley, Kiowa, Elbert, and Freemoni in Colorado eligible for Federal Disaster Assistance.; however, the heaviest damage occurred in Otero County and the City of La Junta. Under authority of the Public Law 84-99, Emergency Levee Rehabilitation and Repair Program; the Corps of Engineers will repair the levees at La Junta, levee toe erosion at Las Animas; and replace riprap lost along the floodway levee in Pueblo. The Corps haci originally constructed all these flood control works. The highest need for flood managememt improvements is in the vicinity of Colorado Springs, Manitou Springs, and La Junta. Further study in each of these areas will likely find that viable flood management solutions e~cist. The Pikes Peak Area Council of C~overnments and the Pueblo Area Council of Governments have formed the Fountain Creek Watershed Forum and have Executive Summary Post Flood Assessment Report v Draft Revised 09/I S/99