First stage contract work on the Durango Pumping Plant included foundation excavation, construction of the concrete intake structure adjacent to the river, and the fish outfall structure. Worked commenced in April 2003 and was completed in August 2004.
The second stage contract, consisting of construction of the fish screen structure, the building housing the pumping units, the intake and discharge piping, the pumps, and landscaping work was awarded to Weeminuche Construction Authority (WCA) in the fall of 2004. The following work was accomplished under the second stage contract.
Concrete construction work for the pumping plant was completed during the summer of 2007. Installation of structural steel for the roofing system on the pump bay portion of the building and the service bay was completed during 2007 with the roofing system being installed and completed during the spring of 2008. Construction of the air chamber, consisting of a fabricated-in-place, 39-foot diameter steel ball, began in the spring of 2007, and has been completed. The roof system for this structure was completed during the spring of 2008. Installation of the fish screens and fish screen cleaning system was complete by 2007 summer’s end. The retaining wall adjacent to the switchyard was completed during the 2006-2007 winter. Western Area Power Administration’s construction of the switchyard and transmission line was completed in the spring of 2008. Work on the Ridges Basin 72-inch diameter discharge pipeline was started early in the summer of 2006 and was completed in the late fall of 2006. Construction work for the discharge line consisted of: 1) excavating a trench for the pipe; 2) placing and welding the mortar-lined steel pipe in the trench; 3) backfilling the trench and partially covering the pipe with soil cement slurry backfill; 4) and, finally backfilling the remainder of the trench back to the original ground surface with trench excavation material.
Overhead cranes within the pumping plant were installed during the fall of 2007. Architectural finish work on the exterior of the pumping plant structure began in the fall of 2007, and was completed in the spring of 2008. Delivery and testing of pumps, motors, and associated electrical began in early 2008 and is now complete. Pump #1 (which had to be re-cast) was installed in late 2008. Commissioning of the motors/pumps was started in April 2009. Testing of the motors/pumps and related systems continued through May 2009. The Plant went on line on June 4, 2009, and steady flows into Lake Nighthorse commenced. Adjustments for the fish screen have been completed. Pumping continued until July 24, 2009, at which time pumps were shut down as flows in the Animas River were below past year medians. Paving of the access road and areas around the Plant was started and completed in July 2009.
Only site work remains to be completed, which includes fencing and final landscaping. This is anticipated to be complete during the fall of 2009.
Northwest Pipeline Inc./Enterprise: The three interstate gas and gas products pipelines owned by these companies were relocated out of the reservoir basin during the summer of 2003. Transfer of right-of-ways has been completed.
Atmos Energy: Atmos’ gas pipeline, which was located in Ridges Basin, has been abandoned. The final alignment selected by Atmos through Twin Buttes is being constructed at this time. Relocation of this gas line is anticipated to be completed during 2009.
County Road 211: The construction contract for Upper County Road 211 Realignment was awarded to Weeminuche Construction Authority on September 29, 2008. Clearing for the road was accomplished in the fall of 2008, as a modification to the dam completion contract. Preliminary earthwork and installation of various cross drainage RCP’s culverts was initiated in 2008, but operations were discontinued during a winter shutdown. Rock excavation by drilling and blasting methods was continued throughout the winter months, and is now complete. The contract completion date for the road realignment is July 9, 2010. The contract is currently approximately 51 percent complete
Tri-State Transmission Line: An agreement for designing and relocating Tri State’s 115-kv transmission line within the reservoir area was put in place during the spring of 2008. Tri-State completed the relocation design in spring 2009, and mobilized their contractors in May 2009. Relocation of the transmission line is anticipated to be completed in August 2009.
Several contracts associated with construction of the dam have been completed by WCA. Excavation for the outlet works tunnel portals was completed in 2003, as was excavation of the right abutment and construction of various haul roads. Under a foundation excavation contract, nearly 2.3 million cubic yards of earth materials were excavated during 2004 revealing the rock foundation for the dam. Also, associated with the foundation excavation contract were construction of more haul roads and some of the drop structures needed for Basin Creek improvements. An outlet works tunnel excavation contract was awarded in 2004 and completed in 2005, as was a contact for supplying and erecting a materials processing plant needed for manufacturing filter and drain materials for the dam.
Dam Completion Contract: A contract for completion of the dam was awarded to WCA in 2005. Work associated with this contract includes: 1) completion of the Basin Creek Improvements; 2) manufacturing of the filter and drain materials needed for these dam embankment sections; 3) foundation grouting for the dam; 4) construction of the dam embankment; and, 5) completion of the outlet works including its intake structure, tunnel lining, control building and associated valves and piping.
Outlet Works Concrete Tunnel Lining: Harrison Western, subcontractor for the concrete tunnel lining construction, has completed placement of concrete for the tunnel’s invert and arch sections. They have also completed placement of the concrete lining in the gate chamber area located near the center of the 1,400-foot long tunnel. The guard gate and piping within the downstream tunnel has been installed. The jet flow, sleeve valve, and associated piping were installed during the fall of 2007 in the control house area.
Materials Processing Plant: The materials processing plant was purchased, set up, and operated for the production of the processed sand and gravel filter and drain zones within Ridges Basin Dam. Dam embankment construction is now complete; and therefore, the plant has been decommissioned and removed from the site.
Outlet Works Control House: Concrete work was begun on the outlet works control house and engine generator house located just outside of the downstream outlet works tunnel portal. Construction of these two concrete buildings continued through the summer, fall, and winter of 2007, and was completed during the spring/summer of 2008.
Dam Foundation Grouting: Blanket hole and curtain hole grouting has been completed from abutment to abutment for Ridges Basin Dam. Grouting associated with the outlet works tunnel and gate chamber was completed during the fall of 2007.
Dam Embankment Construction: Upon completion of grouting work on the lowest portions of the dam foundation during mid-summer 2005, dam embankment placing operations were started. During this first embankment placing season, until freezing weather conditions in November of 2005 stopped the work, WCA was able to place about 30 vertical feet of embankment. Operations involved placement of the clay core; the sand filter and gravel drain zones of the embankment; the upstream and downstream shell zones composed of sand, gravel and cobble pit run material; and the miscellaneous materials zone used for refilling the excavation upstream of the dam embankment.
Dam embankment construction was restarted in April of 2006 and continued on a double shift, five days per week basis through mid-November 2006. By this time, the embankment had been constructed to about Elevation 6775. Embankment construction resumed in April 2007 and continued throughout the spring, summer, and fall of 2007. “Topping out” or completion of the dam embankment occurred in November 2007.Borrow Area B Development: The borrow area has been cleared and completely stripped of topsoil and clay overburden. The borrow area was used as a source area for the sand, gravel, and cobble dam embankment zone, and as a raw material source for manufacturing the sand, gravel drain, and downstream facing element embankment zones. This borrow area has also served to supply materials for construction of drop structures in Basin Creek; to supply materials for haul road sub-grades; and as a raw material source for manufacturing haul road gravel surfacing. Upon completion of the dam embankment, this borrow area has been contoured to flatten steep slopes, topsoil was placed and spread, and seeding activities performed to complete restoration of the borrow area.
Borrow Area A Development: During the initial stages of the dam construction, Borrow Area A was stripped and pre-wetting performed for moisture conditioning. The Borrow Area A was used as a source area for the clay core portion of the dam. The clay material was selectively excavated from naturally occurring deposits of material with optimum moisture content or wetted to condition the material prior to excavation. As the borrow area is entirely within the reservoir area and has been inundated, no attempt at restoration was made.
Other Activities: Construction of Drop Structures 6, 7, and 8 were completed during the 2005-2006 winter season. Construction of the remainder of the drop structures and most of the Basin Creek Improvement work began and was completed in the winter of 2006-2007. Work has been completed for the Basin Creek Improvements upstream of Drop Structure 4. Completion of access roads, gravel surfacing, and dam embankment instrumentation occurred during the spring of 2008.
Reservoir clearing was completed during the summer of 2008. The demolition of existing structures and removal of fencing from within the reservoir area was also completed during this same time frame.
Construction for Ridges Basin Dam is essentially complete with only minor punch list items remaining to be completed. Final electrical wiring and testing at the Control House/Engine Generator buildings, as well as, final operational testing of all mechanical and electrical equipment at the outlet works is underway and is anticipated to be completed during the summer of 2009.
Initial filling of Lake Nighthorse reservoir began in the spring of 2008, with the collection of snowpack runoff and precipitation events within the basin. A maximum depth of 8.2 feet of water from EL 6730 to EL 6738.2 was stored in the reservoir during the 2008 season. Filling of the reservoir resumed in June 2009. Refer to the section below regarding the Lake Nighthorse First Fill.
Lake Nighthorse Boat Ramp: Utilizing funding provided by an outside source, a contract was awarded to Weeminuche Construction Authority in March 2009 for construction of the Lake Nighthorse Boat Ramp. Work on the construction of the boat ramp was completed in June 2009. Negotiations are currently underway for the construction of the ramp’s associated facilities, which includes access road, and parking and sanitary facilities.
Lake Nighthorse First Fill
Filling operations for Lake Nighthorse commenced in May 2009, and continued through July 2009. The Animas River realized peak flows approximately one month earlier than historical averages, resulting in lower than normal flows in July. Pumping was reduced as the river flows decreased in July, and all pumping operations were ceased on July 24, 2009. Filling operations resulted in the storage of approximately 25,000 acre-feet, or approximately 20 percent of the total storage capacity.
The Durango Pumping Plant will remain inactive through the month of August, while personnel conduct the first of four required holding periods. Tentatively, operations will recommence in September 2009, and with favorable hydrologic conditions, the reservoir could be full as early as the fall of 2010.
Ridges Basin Inlet Conduit
Final specifications for the remaining portion of the inlet conduit were completed in February 2006. WCA prepared technical and cost proposals for Reclamation review with negotiations and award of a contract being completed in December 2006. Excavation work for installation of the pipeline began in January 2007. Manufacturing of the steel line pipe was initiated and the first shipments arrived at the site in April 2007. Construction of concrete discharge structures began in the summer of 2007 and was completed in the late fall of 2007. Excavation, placement, and backfilling of the inlet conduit pipeline began in the summer of 2007, and was completed by summer’s end in 2008. Restoration of the disturbed right-of-way was also completed at this time. The right-of-way area has been revegetated. Installation of the cathodic protection system is complete. Testing of the system has been done, and test results are anticipated in August 2009.
Navajo Nation Municipal Pipeline
The permanent right-of-way (ROW) and Temporary Construction Easement for the pipeline was approved by the Bureau of Indian Affairs on September 19, 2008. The Navajo Nation EPA approved the Construction Permit on October 15, 2008.
The city of Farmington (COF) has contracted HDR of Albuquerque, NM, for the design of the portion of the Farmington Reach that passes through the COF. The design has been finalized and the work presented for bidding during the summer of 2009. The work was divided into two contracts. The first contract, the NNMP-Farmington Reach-Pipeline Improvements, consists of approximately 2.4 miles of pipeline extending from the city’s 1C water zone near the airport to a point on the northeast bank of the San Juan River. A bid opening was held on July 21, 2009. The second contract, NNMP-Farmington Reach-Potable Water Tank, consists of constructing a 2 million gallon Concrete Storage Tank. A bid opening was held on July 22, 2009. The award, Notice to Proceed, and site mobilization for both contracts are expected to occur by early fall of 2009.
The Horizontal Directional Drilling portion of the NNMP began following the October 2, 2008 Notice to Proceed. During the spring and early summer of 2009, contractor Southwest Dakota and its drilling subcontractor, Global Underground, completed the drilling of the two San Juan River Crossings. The 24-inch HDPE pipe lines were welded together and pulled through the drilled crossings. San Juan River Crossing #1 was pressure tested and remains to be disinfected and flushed. San Juan River Crossing #2 remains to be pressure tested, disinfected, and flushed. Drilling of the Crossing #3, Nenahnezad Hill, is anticipated to begin in mid-August 2009.
A P.L. 93-638 contract for the construction of the Fruitland Reach portion of the NNMP was awarded to the Navajo Engineering and Construction Authority on September 29, 2008 with Notice to Proceed on December 15, 2008. The reach includes 7.4 miles of 24-inch diameter PVC pipe. Construction of the Fruitland Reach of the NNMP began in March 2009, and continues to progress with mass excavation of the reach completed. Trench excavation, pipe laying, and backfill operations are underway with up to 600 feet of 24-inch pvc pipe placed each shift. Construction of this reach is expected to be complete in January 2010.
A solicitation for the remaining reaches of the NNMP (Nenahnezad, Nenahnezad Tank, San Juan, Hogback and Shiprock Reaches) has been provided to NECA. NECA has provided a proposal for the remaining work. Negotiations are expected to begin in early August 2009 with award of the remaining work anticipated to occur in late September 2009.
When completed, the pipeline will stretch approximately 28 miles and convey 4,680 acre-feet of treated water from the city of Farmington to the Navajo Nation near Shiprock, New Mexico.
Mitigation Area Wetland/Riparian Mitigation
The Mitigation Area has been transferred to Operations and Maintenance status with some punch-list items to be addressed.
Undesirable plant species were eliminated and replaced with desirable species. Vegetative conditions were improved in the upland buffers adjoining the riparian habitats. A new contract for 2009 has been implemented and work in the field is underway.
All mitigation area fencing is complete.
Wetland, riparian, and upland vegetation, as well as wildlife habitat mitigation, development is 100 percent complete. Completion results are included in the April 2008 VEGETATION AND WILDLIFE MITIGATION FINAL REPORT.
On-going strategy development for long-term management continues. Reclamation is seeking contracting opportunities for the Colorado Ute Tribes to manage the Animas-La Plata Project Mitigation Area under Public Law 93-638. A new contract for an interim caretaker has been awarded.
Monitoring of golden eagles and migratory birds in Ridges Basin was terminated upon dam construction completion. Over a 4-year period of reservoir filling and post-filling, monitoring will be performed to determine the effects on territory occupancy. Reclamation awarded a contract in 2009 for various monitoring services. These services include: 1) eagle monitoring in Ridges Basin area; 2) migratory bird monitoring necessary to address Lake Nighthorse first-fill issues; and, 3) Endangered Species Act survey and monitoring for the Navajo Nation Municipal Pipeline in New Mexico.
Pre-testing has been completed and the initial formal test has been scheduled for testing the efficacy of the sleeve valve apparatus for prevention of escape of fish to the Animas River. Full testing will occur during the first hold period at approximately elevation 6800’.
Study of potential ALP project operation effects on Animas River cottonwood recruitment is complete and has been determined to be even less than the previous (larger) project, as expected.
Study design for monitoring Lake Nighthorse mercury bioaccumulation is complete. Reclamation is seeking an MOU or similar tool to work with CDOW to accomplish the sample collections.
Animas River trout mitigation stocking Interagency Agreement has been signed by both the Fish and Wildlife and Reclamation. Stocking began in summer of 2009 as a cooperative effort between SUIT, CDOW and Reclamation. All 2009 stocking is complete (100,000 5” Hofer-CRR hybrid rainbow trout).
Reclamation is complying with environmental compliance on the NNMP construction and has weekly environmental monitoring.
Animas River monitoring to evaluate Project operation effects on young native fish will be conducted in 2009 and 2010. The study design was completed in late 2008. Contracting could not be completed in time for 2009 study samples, so the study data collection will start in 2010.
The ALP Project Environmental Commitment Checklist review for 2008 has been completed.
Call Reclamation's toll free number for the latest construction information by phone: 866-720-0918