|
<br />Fort Collins Flood 1997: Lessons from an Extreme Event
<br />
<br />February 20,1998
<br />
<br />By Neil S, Griggl, Nolan J. Doesken2, David M, FricI2, Mike Grimm4, Marsha
<br />Hilmes,s Thomas B. McKee6, KevinA.Oltjenbruns.7
<br />
<br />Abstract
<br />The July 28, 1997 flood disaster in Fort Collins, Colorado is generally called a "500-year
<br />event" and offers insight into the causes and impacts of extreme urban flooding,
<br />Although it hurt and traumatized many people, the flood provided valuable lessons for
<br />civil engineers, managers of govemment agencies, political leaders, counselors, and
<br />citizens. Representing several disciplines and entities, the authors present a cross-cutting
<br />view of the flg.od emergency and its lessons. The paper also includes a synthesis of a
<br />post-flood conference at Colorado State University which featured reports from all major
<br />entities involved in the flood. The remarkable storm that caused the flood produced the
<br />heaviest rains ever documented to have fallen over an urbanized area in this state in the
<br />recorded history of Colorado. The storm occurred in stages, and dropped 10 to 14 inches
<br />in 31 hours in a large area around Fort Collins. The heaviest hourly precipitation
<br />occurred at the storm's end, which is different from most storms, and may have
<br />exacerbated the flooding. Runoffwas dramatic and some peak discharges greatly
<br />exceeded projected 100-year and 5oo-year flows. The City Manager's report showed five
<br />people dead, 54 people injured, loss of about 200 homes, and 1500 homes and businesses
<br />damaged throughout the City. Fort Collins was more prepared than most cities because it
<br />has a nationally-recognized Stormwater Utility and good emergency response
<br />capabilities, but it still learned much from the event. Damages at Colorado State
<br />University were unusually severe, totaling in the range of $1 00 million, including
<br />building damages, about 425,000 library volumes inundated, loss of a semester's
<br />textbooks in the bookstore, and many other losses-both personal and professional.
<br />Although the university was surprisingly Vulnerable, it responded well with no delay in
<br />opening school a month later, but only as a result of tremendous efforts. Emergency
<br />response in the City by the Poudre Fire Authority was outstanding, and although the
<br />flood had tremendous impacts on the community, not one firefighter or police officer was
<br />injured, Within three months after the flood, the local paper, the Coloradoan, had
<br />published 282 stories about the flood, and the event received broad coverage in the
<br />
<br />I Professor and Head, Department of Civil Engineering, Colorado State University, Fort Collins Colorado
<br />80523.
<br />2 Assistant State Climatologist, Colorado State University, Fort Collins Colorado 80523.
<br />, Regional Vice-President, Ayres and Associates, Fort Collins, Colorado.
<br />4 Floodplain Engineer, Federal Emergency Management Agency, Mitigation Directorate, Hazards Study
<br />Branch, W.shington DC, 20472.
<br />'Flood Plain Administrator, City of Fort Collins, Colorado.
<br />6 State Climatologist and Professor of Atmospheric Science, Colorado State University, Fort Collins
<br />Colorado 80523
<br />7 Associate Professor, Department of Human Development and Family Studies, Colorado State University,
<br />Fort Collins Colorado 80523.
<br />
|