Van Bibber Drainage Improvement Project
Location: Arvada, Colo.
Client: City of Arvada, Colo.
For more than three decades, the City of Arvada and the Urban Drainage and Flood Control District (UDFCD) have worked toward a solution to remove a large portion of the city from the 100-year floodplain.
Expanding the inadequate channel and enlarging the undersized storm drains for Van Bibber Creek (normally a small trickling stream but which, under specific weather conditions, can wreak havoc on homes and businesses) had been an “imminent project” for some time. Manhole covers in the area have been known to blow off, and it is not unusual for businesses to open front and rear doors, allowing floodwaters to flow through their buildings. Finally, after federal funds were appropriated in 2002, the Van Bibber Creek Flood Protection Project got under way.
Multiple master plans by a variety of engineers and planners had been completed in the past, proposing solutions such as an upstream detention dam, off line detention ponds in a soccer complex, a large open channel along the south side of West 58th Avenue, etc. Unfortunately, all the solutions were found impractical from a cost perspective, would not pass a reasonability test or would require the acquisition of too much valuable retail land -- or a combination of all of those factors. Thus, a solution to remove properties from the 100-year floodplain could not move from master plan to implementation.
It was the U.S. Army Corps of Engineers who came up with the idea of a box culvert on a diagonal across the retail shopping areas. It shortened the conveyance mechanism by 1,000 feet and did not require acquisition of two acres of valuable retail property and multiple businesses. The solution only required easements and the removal of one business at the end of a strip retail building. The Omaha District issued Task Orders to Burns & McDonnell under IDIQ DACW45-96-0002 for the detailed hydraulic analysis, final design and construction plans and specifications for the project.
The 6,000-foot project length was divided into three distinct reaches by the nature of adjacent development and topography. The most downstream reach consists of 1,600 feet of double 14.5-foot by 8.5-foot RCB constructed on a curvilinear alignment through two active shopping centers and across Independence Street and West 58th Avenue, both urban arterial roadways.
Extensive and highly detailed demolition, restoration and traffic control plans were required for this segment of the project, which terminates in a reinforced concrete drop structure at Van Bibber’s confluence with Ralston Creek. The coordination and planning of a wide array of utility relocations was necessary.
The central reach of the project, which extends upstream from West 58th Avenue approximately 1,400 feet to Kipling Parkway, was constructed on a former public works department maintenance yard, and consists of a trapezoidal open channel. To provide a stable channel on the steep gradient of this reach, it was necessary to include two grouted stone boulder drop structures with a maximum drop height of 6 feet. This reach also includes a reinforced concrete drop structure with a drop height of 5 feet immediately downstream of existing box culverts on Kipling Parkway, a four-lane divided roadway.
The upstream reach of the project was situated on property known as North Jeffco Park and Recreation District, which was in the process of planning a major redevelopment of its existing recreational facilities. Burns & McDonnell and the local sponsors worked closely with the Recreation District to develop a design closely coordinated with those redevelopment plans and that met the project flood protection requirements. A series of highly differing channel sections were included in this reach, which also included a new roadway bridge for access to the park, two grouted stone boulder drop structures, and modifications to an existing roadway bridge at its upstream end.
Arapahoe Utilities and Infrastructure (AUI) was the contractor for this project. The job was completed with zero work injuries and the Corps of Engineers named AUI Outstanding Contractor of the Year.
The Corps of Engineers’ solution was the impetus to get the approximately 40 residences and 90 businesses out of the 100-year floodplain. Cost of the project was about $12.5 million with the Corps of Engineers participation being $7 million and the local agencies (Urban Drainage and Flood Control District and the City of Arvada) sharing the balance, $5.5 million fifty-fifty.
Once construction was initiated it was completed on schedule and within budget parameters. Promises were made and kept to the business community to avoid construction in the retail area during the holiday season and prevent road closure or detours until after the holiday season.
The key to making this project successful was the cooperation between multiple federal, state and local agencies, coupled with the involvement of affected businesses. From the onset of the project, business owners were well-informed and their input solicited. In all, more than 40 homes and 90 businesses were removed from the floodplain, and underperforming commercial areas are now ready for redevelopment. FEMA has issued a CLOMR for this project, removing substantial areas of Arvada from the regulatory floodplain.