The Brighton Ditch Company discovered a severely damaged diversion dam at the conclusion of the 2003 irrigation season.
The Brighton Ditch diversion dam across the South Platte River was found to have severe structural damage
requiring rapid design of a repair to be implemented during the winter prior to the irrigation season.
Steel sheet piling is being driven along the upstream face of the repair section.
Deere & Ault staff evaluated the damage and presented repair alternatives to the Brighton Ditch Board of Directors. The investigation revealed major structural damage to the existing spillway slab, cavernous voids under the existing concrete structure, continuing soil loss due to undermining flows beneath the check dam, erosive damage to the river banks, and river sedimentation and channel instability upgradient of the dam.
Deere & Ault developed repair alternatives along with anticipated construction costs. After reviewing these alternatives, the Brighton Ditch Board of Directors selected an alternative consisting of a basic repair to the undermined section of the check dam spillway. Deere & Ault staff completed a rapid turnaround of the design and secured bids from three local contractors familiar with river construction projects. The winning bid came in at the cost estimated by Deere & Ault staff, and the repair work was authorized to commence. Subsequent examinations of the structure during demolition revealed additional damage to the foundation and supporting substrate. Revised plans were developed within two days and the work continued without interruption.
Sheet pile cutoff walls were driven upstream and downstream of the damaged section of spillway to provide a hydraulic cutoff. Unsuitable subgrade, including car bodies, was removed from the foundation area and engineered fill was placed between the sheet pile walls. A new reinforced concrete spillway slab was installed. This new slab included integral pile caps completing the hydraulic cutoff.
Clients: Brighton Ditch Company