Suggested Title Page

Pamphlet Outline

Opening Statement

Decisions Resulting in Public Exposure To Flood Loss

Selected Refrences


Completed Sections:

The Boulder Creek Flood of [date]



Suggested title page:

The Boulder Creek Flood of [date]:

A Community Choice

[Name of Coordinator]

[Names of Fieldworkers]

Prepared with support of a grant
to the University of Colorado
from Gilbert F. White



Printed and distributed under the supervision
of the Natural Hazards Research and Applications
Information Center





Boulder Creek Flood Pamphlet Outline

(August, 1994)

Title Page
Table of Contents
Introductory Statement: Gilbert White
Decisions Resulting in Location of Public Buildings (not completed)
Effects of the Boulder Creek Flood

  1. Lives and Major Injuries
  2. Property Damage
  3. Social Disruption
  4. Floodplain Habitat and Amenities
  5. Warning Systems

Selected References



Opening Statement - Preface

This brief report on the consequences of the Boulder Creek flood of (Month, day, year) is intended to provide an initial estimate of the catastrophe and an outline of the decisions leading to it. From it, the citizens of Boulder may be helped to understand how their community came to be vulnerable to the flood, and the kinds of decisions that may either reduce or enlarge the human consequences of the next large flood.

The field work immediately following the flood was financed from a grant made to the University of Colorado in 1992 by Gilbert F. White, who first became interested in what was happening on the Boulder Creek floodplain in 1957, and who in 1994 described the major decisions made prior to that year.

The materials in this notebook were assembled in 1993 - 1994 by Sharon Gabel under the direction of Gilbert F. White. They were written in the knowledge that another great flood on Boulder Creek might rival or exceed that of May, 1894, at some time in future but that the year was entirely unpredictable. In those circumstances the suggestions as to problems and suitable field methods may turn out to be on the mark or greatly deficient. Depending upon the conditions then prevailing, the suggestions herein may require much or little revision. It is expected that whomever serves as coordinator will exercise her/his best judgement as to what then seems suitable. The goal is simple: to promptly inform the citizens of Boulder appropriately.



Decisions Resulting in Public Exposure to Flood Loss

Some citizens of Boulder surveying the effects of a Boulder Creek catastrophe may ask how this came about. There has never been any doubt that great floods occur, although over the years there have been differing estimates of their frequency.

The causes of flood loss are to be found primarily in the decisions of individuals and public groups to expose themselves or others to the ravages of flood water. These were decisions to build or not build in floodplains, to prepare or not prepare to cope with high water when it comes, and to share knowledge with other people of how to mitigate losses.

The net effect of various developments in the 1% floodplains after the great flood of 1894 was roughly as follows to 1978 (when the latest comprehensive surveys were made):

to 1936 269 new single-family buildings
57 commercial buildings
3 transport buildings, and
3 public buildings had been added
Between 1936
and 1978
47 single-family buildings
43 multiple-family buildings
197 commercial buildings
38 industrial buildings
12 transport buildings
26 public buildings had been added

After 1978 there was further increase, much of it the result of extensive construction by the University of Colorado, including student residences.

The decision processes leading to increased public exposure have been complex. There is no simple explanation. From several studies that have been made it is possible to specify in abbreviated form the principal decisions, and to note some of the factors affecting them (Gruntfest, Phillipsborn, Smith, and White, et al.). From these, it is possible to suggest several simple observations and lessons that may be pertinent as Boulder looks ahead to the next flood.

Key Decisions
A report by Olmstead on public and recreational land use recommends that the floodplain not be used for buildings. A similar recommendation was made by engineers Metcalf and Eddy. Neither was accepted by the City Council.

Under authority of the Flood Control Act of 1936, Army Corps of Engineers recommends channel and levee construction to protect areas in the floodplain with federal-municipal cost sharing. This was rejected by the City Council that, in 1951, decided to build a new Municipal Building at a location on Broadway between the channel and proposed levee line, with the floor level one foot above 9,000 cfs flow (a later Corps report estimates the 1894 flood was 8 feet deep at that site).

Following a consultant's study of floodplain use, and after the Platte River flood of 1969, Council enacts floodplain regulations to prohibit building in the floodway and to guide development in other parts of the floodplain. City qualifies for participation in the national flood insurance program.

The Public Library was built in the floodplain.

Following a disastrous flood in 1976 in Big Thompson Basin, the city, county, and NOAA join in design and establishment of a flood prediction and flood warning system to facilitate emergency action.

Revised flood hazard maps are issued by the city, and public acquisition begins of selected buildings obstructing the floodway below Broadway.

Council authorizes and builds a library addition slightly above the 13,000 cfs flood level but constricts the creek with a new foot bridge. Council first authorizes and then withdraws a plan for new Civic Center construction at Canyon and 13th.

The city uses the centennial of the 1894 flood to focus public attention on flood vulnerability and on possible mitigation measures.

The Decisions in Retrospect
Looking back over the 100-year experience, a few observations seem to emerge.

  1. The uncertainty about the measurements and estimates of the frequency and volumes of flood flows makes it difficult to accept precise numbers on which to base plans. Thus, the early estimates that the 1894 maximum flow was 7,000 cfs were subsequently revised to 13,000 cfs, and controversy continues as to its frequency.
  2. There is no clear public policy as to the degree of risk for which individuals or agencies find it acceptable to prepare. For example, it is known that a flood much larger than 1894 occurred some time after the last glaciation, and estimates have been made of the magnitude of a "500-year flood" in contrast to the "100-year flood" used as a minimum criterion for regulation by the Federal Insurance Administration. The city does not attempt to regulate land use above the estimated 1% flood elevation.
  3. Many decision makers find it difficult to contemplate a very rare event occurring during their expected term of life or office. There is a strong tendency to say "It won't happen in my lifetime" or "I will take a calculated risk," but without being able to state the risk precisely.
  4. It is far less difficult to value a direct economic cost or profit than a loss of human well-being or life. Thus, a City Council can calculate the gain from building on floodplain land already owned by the city, thereby saving land costs, but has trouble estimating the later public gain from saving a human life by not building in a hazardous area.
  5. Federal policies of providing disaster loan and grant assistance to flood sufferers and of providing subsidized insurance to people already occupying hazardous areas may encourage new or continued exposure to flood hazard. While persons purchasing floodplain property with federally-insured mortgages may be required to purchase flood insurance on existing structures, but not at actuarial rates' Other property owners need not. In recent years the federal agencies have offered increasing proportions of loans and grants to assist private and public flood sufferers. This has tended to reduce the incentive to insure, to take mitigating actions or to avoid hazardous locations.

Positive Action After a Flood
Bearing these and related problems in mind, it may be important for the people of Boulder to consider some or all of the following actions in addition to taking measures to relieve immediate human suffering.

  1. Estimate what would have been the physical and social consequences if a flood as great as the so-called 500year flood had occurred to better inform people of the hazard.
  2. In carrying out assistance and repairs, determine what mitigation measures could be taken at the same time to reduce the losses when the next flood of similar or larger size occurs.
  3. Compare the costs and benefits of continuing the prevailing land use with the costs and benefits of shifting to selected different land uses, including evacuation of designated areas.
  4. Consider what other action should be taken to reduce the community's vulnerability to future disaster.
Experience in other areas suggests that unless these and related actions are taken promptly, the interest in pursuing them will fade rapidly. It also suggests that the likelihood such measures will be adopted will depend in no small measure upon the initiative and persistence of a few citizen groups in investigating them. The basic challenge is for Boulder to emerge from the recent disaster with the means and determination to prevent it from happening again.



The Boulder Creek Flood: Selected References

Most of the references listed below are located in the Natural Hazards Research and Applications Information Center (NHRAIC) Library, at 1244 Grandview Ave. Those documents not carried by the NHRAIC Library can be found either in one of the collections of Gilbert F. White's personal papers on the Boulder Creek Floodplain. These collections are located at the Western History Collection of the University of Colorado (Boulder) and at the Carnegie Branch of the Boulder Public Library. Additional items may be found by searching the Colorado Area Research Library (CARL) system. Searches should first be done on the University of Colorado (Boulder) Norlin Library database. The Carnegie Library Collections can also be accessed using CARL, and are registered under call numbers 764 and 765.

Amick, R. "Emergency Operations Plan: Flood Disaster Management". Boulder: Univ. of Colorado Police Dept., 1992.

Association of State Floodplain Managers. Realistic Approaches to Better Floodplain Management. Boulder: NHRAIC, 1987.

Betancourt, Terri L. A GIS Extension to Preparedness Planning for Boulder Creek Floods. Master's Thesis, Dept. of Geography. Boulder: Univ. of Colorado, 1989.

Callen, Lon. "City of Boulder Incident Command System (BICS), Operations Manual." Boulder: Emergency Preparedness Office, 1991.

City of Boulder Planning Board. "Memorandum: Land Use Implications of Proposed Flood Zones" Boulder: Planning Board, 1988.

City of Boulder, Dept. of Planning and Community Development. A Plan for Boulder Creek. Boulder: 1984.

Colorado Water Conservation Board. "A Report on the Vulnerability to Flood Losses on the Campus of the University of Colorado, Boulder." Denver: CWCB, 1986.

Cornett, Linda. "Floodway Definition Should Change: Panel" The Daily Camera, Jan. 9, 1985.

Cornett, Linda. "$50 Million Recommended to Prevent Flood Damages" The Daily Camera, April 6, 1985.

Cornett, Linda. "Issue Gets Flood of Comments" The Daily Camera, May 6, 1985.

Dane, Sylvia. "Public Land Use and the Floodplain: An Analysis of the Boulder Civic Center Siting Process". Unpublished paper, University of Colorado - Denver: Graduate School of Public Affairs, 1993.

de Raismes, Joseph N. "Memorandum: Should Further Development Be Banned from Floodways and Other Hazard Areas?" Boulder: City Attorney's Office, Jan. 30, 1987.

Downing, Thomas E. Warning for Flash Floods in Boulder, Colorado. (Working paper # 31) Boulder: NHRAIC, 1977.

Downing, Thomas E. and Eve C. Gruntfest. Scenario of the Boulder Flash Flood with Eyewitness Accounts. Boulder: Inst. of Behavioral Science, No Date Given.

Federal Emergency Management Agency (FEMA). Flood Insurance Study, City of Boulder, Colorado. Washington: FEMA, 1990.

Flack, Ernest J., Barbara B. Greenlee, Roger Hartman, and L. Scott Tucker. Master Plan for Boulder Creek Tributaries. Boulder: City Council, 1985.

Gillen, Sharon. "County Ready for Major Flood" The Daily Camera, May 17, 1983.

Gruntfest, Eve. Changes in Floodplain Land Use and Flood Hazard Adjustment in Denver and Boulder, Colorado, 1958-1979. Ph.D. dissertation: Dept. of Geography. Boulder: Univ. of Colorado, 1981.

Gruntfest, E. C. What We Have Learned Since the Big Thompson Flood. Proceedings of the 10th Anniversary Conference. NHRAIC, Special Publication # 16. Boulder: Natural Hazards Research and Applications Information Center, 1986.

Havlick, Spenser. "Boulder Hasn't Done All It Should to Protect Against the Flood" The Daily Camera, May 21, 1989.

Hoffman, Bill. "Flood Waters in the Boulder Valley - A Year Later" The Daily Camera, May 10, 1970.

Hoover, C. Rusnock and Carol Chorey. "The Flood of '94" in The Daily Camera, May 29, 1994, pp. 1A, 8A-10A.

Ketta, Moussa, Timothy Shangraw and Keith Ferguson. Economic Analysis of Uncertainty: Property in the Boulder Flood Plain. (NHRAIC Library) 1977.

Koltnar, Barry. "Floodplain Semantics Evoke Council Fireworks" The Daily Camera, Dec. 19, 1973.

Love, David J. Analysis of High Hazard Flood Zone. Boulder: Love & Assoc., 1987.

Love, David J. 100-Year and 500-Year High Hazard Flood Zone Study: Boulder Creek (6th St. to 17th St.). Boulder: Love and Assoc., 1992.

McGrath, Sally. "Planners Like Buying Land as Flood Control" The Daily Camera, December 20, 1985.

McGrath, Sally. "Voters Pick Downtown Library Site" The Daily Camera, Dec. 7, 1988.

McGrath, Sally. "New Flood Rules Planned: Development in High Hazard Areas to be Banned" The Daily Camera, 1989.

Oaks, Sherry D. Floods in Boulder County, Colorado: An Historical Investigation. Boulder: NHRAIC, 1982.

Olmsted, Fredrick Law, Jr. and Charles Eliot. The Improvement of Boulder, Colorado. Boulder: Boulder City Improvement Assn., 1910.

Philipsborn, Randall H. Decisions to Construct New Buildings Within the Regulatory Floodway of Boulder Creek: 1959 - 1978. Thesis, Dept. of Geography. Boulder: Univ. of Colorado, 1978.

PLAN Boulder County. "Memorandum: Floodplain Management Along the Boulder Creek Tributaries" Boulder: PLAN Boulder, Sept. 8, 1985.

Roberts, Chris. "Boulder Flood Plans Emphasize Preservation of Life - Not Property" in The Daily Camera, July 7, 1988.

Roberts, Chris. "Flood-Zone Proposal Draws Fire: Property Owners Voice Concern About Values" in The Daily Camera, July 14, 1988.

Smith, Phyllis. History of Floods and Flood Control in Boulder, Colorado. Boulder: (Carnegie Library), 1987.

U. S. Army Corps of Engineers Committee on Environmental Planning (CECEP). Flood Control Plan: Boulder Creek. Boulder, CECEP, Oct. 8, 1973.

U. S. Army Corps of Engineers. "Boulder's Flood Protection Decision: A Choice to Live With..." Boulder: (Carnegie Library), 1977.

White, Gilbert F. Human Adjustment to Floods. Chicago: University of Chicago Press, 1945, pp. 1 - 2, 205 - 212.

White, Gilbert F. "The Changing Scene in 17 Areas, 1936 - 1957: Boulder, Colorado" in Changes in Urban Occupance of Floodplains in the United States. Chicago: University of Chicago Press, 1958, pp. 94 - 100.

White, Gilbert F. "Flood Hazard Reduction and Floodplain Regulations in Boulder City and County, Colorado." Report to City of Boulder Planning Dept. and Planning Commission. 1966.

Wright, Kenneth R. "Floodplain Occupancy: Failures in Local Government" National Conference on Floodplain Management, July 23, 1974.