Civil Engineering, Legal, and Political Collaboration: Solving Denver’s Drainage Infrastructure Dilemma

Like many metropolitan areas in the 1960s, the Denver area experienced unplanned and disorganized growth. Suburbs developed around the core city and then incorporated, creating a hodge-podge of agencies, policies, and administrations that often competed for resources, and focused on water and sewer infrastructure rather than drainage. It is easy to disregard where your city’s runoff is going, particularly if it seems like the entity upstream is sending more water your way than it should.

Ironically, Denver’s arid climate also contributed to drainage problems. A dry gulch or channel is easier for developers to fill in than a channel with perennial flow, but both are essential for drainage when it rains. Another factor contributing to runoff problems was the increase in impervious areas resulting from development and downstream drainage bottlenecks.

The Denver metro area suffered a disastrous flood in 1965 that destroyed twenty-five bridges and caused over $500 million in damage stretching from Littleton to Julesburg (“A History of Accomplishment” 2007). This was followed by the then-wettest year in Denver history in 1967 (Fig. 1). The record of 1967 was surpassed by 1969, which became the new record-breaking year for precipitation in Denver (Wright 1970b). Flooded underpasses and water-damaged neighborhoods near the city center were too common during these years. Citizens asked for solutions, but leaders did not know how to implement appropriate actions. Orderly drainage seemed outside of their grasp.

By early 1967, about thirty-five engineers collaborated to become the “Five-County Engineers Group,” which formed an urban drainage subcommittee to address serious drainage problems in Greater Denver. The Urban Drainage Advisory Committee of The Denver Regional Council of Governments (DRCOG) collected funds from member governments and assistance from the U.S. Department of Housing and Urban Development to hire me to develop the 1969 criteria manual.

The need for the manual was propelled by consultants’ surveys that established that there was little commonality in the way that the governmental agencies approached drainage planning and design. Most of the drainage design engineers used the Rational Method for drainage design. Its fundamentals were generally poorly understood and, in most cases, improperly implemented, resulting in drainage systems that were undersized, oversized, or out of hydrologic balance. Based on data from two rain gauges and three discharge gauges installed by the City of Denver at Harvard Gulch (Figure 2), a regional unit hydrograph approach to Denver storm drainage was begun for system sizing (Lorah and Wright 1970).

The resulting manual, published in March of 1969, presented a drainage philosophy and policy and explained the procedures required to achieve a comprehensive, multi-means approach to solving urban drainage problems. Policy was developed by a team of specialists to address four principles:

The two-volume, 800-page manual was primarily a set of technical criteria to be adopted by governmental entities. It reflected current best practices and the state-of-the-art; it was organized for easy updating as practices evolved. The design content was determined through a process involving rigorous review of what worked and did not in other cities, both modern and ancient. Data were collected from government agencies including the Denver Department of Public Works, the Bureau of Reclamation, the U.S. Army Corps of Engineers, and the Soil Conservation Service (now the Natural Resources Conservation Service).

The most valuable outside aid was provided by the Federal Housing Administration, whose drainage and flood control expert, D. Earl Jones, Jr., joined our team and proposed a “dual system” approach (Jones 1967). This meant that engineers would plan minor storm drainage systems consisting of storm sewers, curbs, gutters, etc., alongside major storm systems for large, infrequent (one hundred-year) storms. This method was adopted in Denver and throughout the United States and is still in use today.

Concurrent with the development of the manual, Drainage Committee member and State Senator Joe Shoemaker was sharing the committee’s concerns with the rest of the legislature. Shoemaker, also a mentor of our team, served as chair of the state legislature’s Joint Budget Committee, so people listened. He developed a 181-page package that became Senate Bill 202. The Urban Drainage and Flood Control District Act was passed in May and went into effect the following June 14, 1969. It provided for a board of directors of fifteen people consisting of the mayor of Denver, three Denver city councilmen, five county commissioners, four suburban mayors, and two engineers. The District was charged with instituting floodplain zoning, constructing new, major drainageways, building or requiring storm sewer systems, and approving all drainage works affecting more than one governmental entity.

The new District immediately began establishing priorities for necessary corrective actions in the Denver metro area. A major goal of the District was to work with recreation districts and park departments to undertake joint programs on gulches and other waterways. This allowed not only the development of good floodways, but open space and greenbelts. The District soon proved that effective floodplain zoning is important not only for reducing the costs of urban flooding, but for a high quality of life in metropolitan areas.

One could say that national flood control began with President Johnson and the Task Force on Federal Flood Control Policy chaired by Dr. Gilbert White. Johnson sent the “Unified National Program for Flood Control” to Congress in August, 1966. D. Earl Jones, Jr., acting chief of the Land Planning Section of the Federal Housing Administration, was another great thinker who was focused on shaping the national drainage policy of the time; Jones was heavily involved in drainage activities in all fifty states (Jones 1967).

Modern Denver flood control began with the Five-County Engineers Group, chaired by Ted Dieffenderer, director of operations for the city of Boulder, Colorado. Also involved were Horace Smith, deputy city engineer of Denver; Fred Woolley of the Mountain States Concrete Pipe Association; J. K. Smith, head of the Denver Regional Council of Governments; and Art Patton of the Public Service Company of Colorado. Colorado State Senator Joe Shoemaker, an engineer and attorney, and former Denver public works director, had first-hand knowledge of the area’s drainage problems. He was instrumental in getting the group’s concepts through the state legislature, as was Governor John Love, who signed the bill.

U.S. Geological Survey hydrologists Ted Moulder and Ed Tripp helped develop a research program that was instrumental in shaping regional drainage policy. Policy issues for the first Denver Urban Drainage and Flood Control Manual were the result of regular meetings and collaboration with D. Earl Jones, Jr., Joe Shoemaker, University of Chicago urban planner John Sheaffer, and me as a consulting engineer (Sheaffer et al. 1982). I prepared the manual in a twelve-month period, and became the first “technical staff” for the Denver Urban Drainage and Flood Control District, serving under James Quinn, P.E., the first administrator to serve as its director (Wright 1970a).

An independent environmental design group provided ideas on urban environmental concepts. The group included landscape architect Gerald Kessler, planner Weyland Walker, environmental activist Ruth Wright, architect Roger Easton, and me, with input by Dr. Betty Willard and Dr. Gilbert White.

The Colorado legislature listened to the engineers, lawyers, and administrators and believed them. The members of the legislature overwhelmingly supported the recommendation and quickly passed the needed legislation.

Acting for the common good was the driving force behind the comprehensive combined effort by engineering, legal, political, and institutional interests to reconfigure the Denver area’s approach to the drainage and flood control dilemma in which we found ourselves in the late 1960s. There was little other impetus for dozens of busy professionals to take on the seemingly impossible task of bringing together nearly three dozen local governments to speak with one voice on drainage and flood control.

The multitude of activities taking place all at one time by numerous engineers was feasible because of the desire to bring order out of the existing regulatory chaos and the lack of common goals and objectives.

The District took out a loan of $165,000 during its first year and got to work. Subsequent years were financed by a levy of $500,000 without a vote and without bond issues. Immediate beneficiaries of the new drainage policy, practices, and criteria included the downtown Denver Skyline Urban Renewal Project, the Village Green Development, Stapleton International Airport, and the College-view Development.

By February 10, 1970, thirty-six communities in twenty-two states and the District of Columbia, and five foreign countries were studying the Urban Storm Drainage Criteria Manual for use in their own regions (Wright 1970c). The manual was quickly adopted by all thirty-two governments in the Denver metro five-county area. The policy, planning, and design concepts were tested over time, mostly held up, and in some cases were revised as necessary. The city of Boulder and Jefferson County were early adopters of principles in the manual, both initiating recommended detention ponding requirements by 1971.

Flooding in the Denver metro area is an exceptional occurrence these days, and generally minor and well managed. The Denver Urban Drainage and Flood Control District serves an area of over 1,600 square miles with an annual budget of $22 million (A History of Accomplishment 2007). The district operates four distinct programs: master planning; design, construction, and maintenance; floodplain management; and information services and flood warning. These services collectively function to help local governments administer all facets of drainage and flood control practice and policy. The use of new, state-of-the-practice technology allows better, more accurate planning on a regional basis. Slide-rules have given way to computer models and problem areas are tracked using geographic information systems instead of push-pins in a map, but the principles and goals are still the same.

The Urban Storm Drainage Criteria Manual, still in use, was revised in 2000 by Wright Water Engineers, Inc. and is now accessible on the Internet (http://www.udfcd.org/downloads/dowṉcritmanual.htm). The manual provides the governing design criteria for thirty-eight cities and counties in the Denver metro area, and covers a full range of conditions from rural to highly urban. It has been distributed to over 1,000 cities and counties throughout the United States, as well as many other countries.

In the 1960s, city, county, state, and federal engineers; lawyers; and politicians knew the Denver metro area had a drainage and flood control problem, but didn’t know how to solve it. The process of identifying problems openly and seeking solutions collaboratively was the real success in solving Greater Denver’s drainage crisis. People with the strength, courage, and foresight to recognize and investigate difficult issues are bound to get further than those who are defensive, accusatory, or dependent on others. The willingness of about fifty dedicated engineers, lawyers, and politicians to search and strive made all the difference. We owe a lot to these institutional pioneers of four decades ago.