Approximately 1,800 feet of the Ewing Ditch at the base of Ski
Cooper had to be stabilized after the ditch jumped its bank. 
D&A staff provided the Board of Water Works of Pueblo,
Colorado with ditch stability analysis, design, and construction
management services for the Ewing Ditch restoration.

The Ewing Ditch, a transmountain diversion, jumped its bank at the base of the Ski Cooper Ski Resort near Leadville, Colorado, and carved a new channel through approximately 1,800 feet of U.S. Forest Service land.  The ditch was heavily eroded with unstable banks 20 to 30 feet high.  Numerous trees were sloughing into the ditch. 

The Board of Water Works of Pueblo, Colorado (Board) owns and operates the Ewing Ditch.  D&A staff investigated alternatives to convey ditch and storm water flows through the newly formed channel on Forest Service property.

Hydrologic, hydraulic, and sediment transport analyses were conducted.  A subsurface soils investigation was conducted.  Survey information was gathered and a topographic map of the ditch and nearby area was generated.

Technical specifications and contract documents in addition to design plans were developed for this project.

D&A staff assisted the Board in obtaining the Forest Service permits necessary to complete the construction.  D&A staff provided construction management services.

Client: Board of Water Works of Pueblo, Colorado

Wurtz Ditch Restoration
Lake County , Colorado

Approximately 700 feet of the Wurtz Ditch near the Continental
Divide experienced severe erosion. D&A staff provided the
Board of Water Works of Pueblo, Colorado, with a ditch
restoration design and construction management services to
restore and protect the ditch from future erosion.

D&A staff reviewed the State Engineer’s Office records for the Wurtz Ditch and determined the flow rate at which to design restoration measures. A hydraulic analysis of existing and proposed improvements was conducted. Survey information was gathered, the site was flown, and a topographic map of the Wurtz Ditch and surrounding area was generated. The base map was utilized in the preparation of the design plans.

Design improvements at the Wurtz Ditch included:

D&A staff assisted the Board in obtaining U.S. Forest Service permits necessary to complete the ditch restoration measures. D&A staff provided construction management services.

Columbine Ditch Restoration
Climax, Colorado

Reconstructed Transmountain Diversion Canal located at the
Continental Divide high in the mountains of Colorado.

The Columbine Ditch is a transmountain ditch that conveys Eagle River basin water to the Arkansas River. At the Continental Divide, approximately 1,100 feet of the Columbine Ditch experienced severe erosion. The Board of Water Works of Pueblo, Colorado (Board) owns and operates the Columbine Ditch. D&A staff investigated channel stability options and provided a channel stability design for the Board.

D&A staff recommended a riprap lined channel design. The benefits include: long-term stability, cost, and future aesthetics. Through cooperation with Climax Mine, D&A staff obtained a riprap source within a four-mile haul distance of the project. After side slope vegetation was established, willow plantings along the ditch provided additional erosion protection.

D&A staff provided the following services: hydraulic analysis, design, bidding assistance, and construction related engineering.

Client:  Board of Water Works of Pueblo, Colorado

Brighton Ditch River Diversion Dam Repair
Brighton Ditch Company, Colorado

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.

The Brighton Ditch Company discovered a severely damaged diversion dam at the conclusion of the 2003 irrigation season. D&A 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.

D&A staff 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. D&A 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 D&A 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.

Client:  Brighton Ditch Company

Farmers' High Line Canal Lining Project
Golden, Colorado

Ponding tests on canal indicated large seepage losses. A low
permeability liner was designed to reduce seepage losses.

The Farmers’ High Line (FHL) Canal provides water to irrigators and municipalities in the North Denver Front Range area. Portions of the canal were suspected of losing large quantities of water through seepage. D&A staff studied several reaches of the ditch and located a prime section for lining. Three alternative lining techniques: concrete, geosynthetic clay liner, and clay earth fill liner were prepared for bidding with construction drawings and specifications. A one-mile section of canal was selected to be lined during the first phase of the project.

D&A staff provided initial investigations to quantify the seepage along the canal. This work included geotechnical review and investigation work, installation of piezometer sets, groundwater monitoring including geochemical tracking, and ponding tests along the canal. These initial investigations identified sections of the ditch with high potential seepage loss rates.

A design was conducted for the section of canal with the largest seepage loss rate. The design work included topographic surveying, hydraulic modeling, design of drop structures and grade control structures, channel section designs, geotechnical investigations, and the development of construction drawings and specifications. D&A staff provided bidding assistance including developing a list of qualified contractors invited to bid the project.

D&A staff provided construction related engineering services.

Client:  Farmers’ High Line Canal and Reservoir Company

Improvements to existing ditches to provide enhanced
conveyance and winterization.

Centennial Water and Sanitation District has contracted with D&A staff to provide engineering services for the construction of a 6,800 acre-foot reservoir. To fill this reservoir on a year-round basis, D&A staff has also been contracted to design modifications to the Last Chance Ditch and Nevada Ditch. Modifications to these ditches included: new main ditch measuring flumes, modifications to the valve works and energy dissipation structures at the downstream end of the Chatfield Reservoir outlet pipes, construction of buried ditch conveyance conduits, new diversion facilities, remote operating and monitoring equipment, and construction of inverted siphons conveying ditch flows across a 25,000 cfs bypass channel, which D&A staff designed as part of the reservoir project.

D&A staff guided this project through intensive review by the Ditch Companies’ engineer and major shareholder, the Denver Water Department. Coordination and permit activities also involved the U.S. Army Corps of Engineers, Colorado Department of Transportation, and the South Suburban Parks Department.

D&A staff provided construction management services associated with the improvements to both ditches.

Client:   Centennial Water and Sanitation District

Surface water is diverted from the Rio Grande into the Closed
Basin for recharge of a shallow aquifer. The groundwater is
subsequently pumped from the aquifer and used to irrigate crops.

The lands served by the Prairie Ditch and San Luis Valley Canal lie largely within what is known as the “Closed Basin.” The Closed Basin occupies the northern portion of the San Luis Valley, and is separated from the Rio Grande’s alluvial valley by a low topographic divide and a shallow groundwater divide oriented roughly parallel to the river. Water imported into the Closed Basin does not naturally return to the Rio Grande.

The Prairie Ditch and the San Luis Valley Canal Companies recognize that continued importation of direct flow surface water from the Rio Grande, in conjunction with groundwater recharge, is crucial to sustaining the shallow groundwater reservoir that allows the continuing operation of their center pivot sprinkler systems. To this end, Company shareholders have constructed groundwater recharge facilities to artificially recharge groundwater.

D&A staff performed an investigation of the historical water use practiced by the Prairie Ditch and San Luis Valley Canal Companies. The objectives of this investigation were to confirm their historic practice of recharging the unconfined aquifer of the Closed Basin, and to present a methodology and accounting procedure to quantify the volume of recharge to the unconfined aquifer of the Closed Basin from their water rights.

D&A staff also performed a hydrologic analysis of the Closed Basin, updating the location of the groundwater divide. D&A staff provided expert witness testimony on the Prairie Ditch Case, which was settled in late-2001. The San Luis Valley Canal Case has been decreed.

Client:  Prairie Ditch Company and San Luis Valley Canal Company

Ditch Company Review Work
Colorado Front Range

Boulder and White Rock Ditch near Niwot High School.

D&A represents numerous ditch companies throughout the Front Range of Colorado. D&A assists the ditch companies in the review of bridge crossings, culvert crossings, pipeline utility crossings, storm pipe acceptance, development, easements, trail and path construction near ditches, diversion and headgate structures, flow measurement devices, ditch relocations, and bank stability measures.

A partial list of ditch companies that D&A represent includes the following: