The project is located at the existing Red Rock Dam, operated by the USACE in central Iowa, near the City of Pella. The prequalification documents became available on 4 September 2012.
The project will divert water from the existing sluice and spillway outlets of the dam to a new powerhouse that will house two identical vertical Kaplan hydraulic turbines, directly connected to synchronous generators. The powerhouse will be equipped with an overhead bridge crane to lift the turbine generator equipment for installation and future maintenance. The construction contract includes, but is not limited to, the following:
• Detailed design, construction, and removal of cofferdam to facilitate construction of the permanent intake structure;
• Deep excavation or tunneling of two water conduits connecting the intake structure with the upstream face of the existing concrete gravity dam;
• Removal of concrete from the existing gravity dam to allow penetration of the water conduits through the dam;
• Deep excavation or tunneling of two water conduits connecting the gravity dam penetrations to the powerhouse;
• Excavation for the powerhouse structure;
• Foundation preparation for the powerhouse;
• Construction of the approach and tailrace channels;
• Construction of the cast-in-place reinforced-concrete intake structure;
• Construction of cast-in-place reinforced-concrete linings for the two water conduits upstream of the gravity dam;
• Construction of cast-in-place reinforced-concrete lining of the water passages through the existing gravity dam;
• Construction of cast-in-place reinforced-concrete linings for the two water conduits downstream of the dam;
• Construction of the cast-in-place reinforced-concrete powerhouse;
• Detailed design, supply, delivery, installation and testing of intake hydromechanical equipment including trashracks, trashrake, wheel gates, maintenance bulkheads, and appurtenant equipment;
• Detailed design, supply, delivery, installation and testing of the powerhouse crane, and balance of plant mechanical/electrical equipment;
• Installation, testing, start-up, and commissioning of Owner-furnished Kaplan turbine-generator units, with appurtenances up to and including the main power transformers;
• Construction of the switchyard and the transmission line to the edge of the property line;
• Installation, testing, startup, and commissioning of Owner-furnished switchyard equipment;
• Construction of site facilities; and
• Miscellaneous other site work including finish grading, roads, parking areas, lighting, fencing, final restoration, etc.
Construction is expected to run from August 2013 to August 2016. Detailed design of the project is currently underway. It is currently anticipated that bidding documents will be issued on 25 February 2013.
Completed prequalification questionnaires for the project will be received by MWH at the address indicated below until 12:00 p.m. (noon) Central Standard Time on 3 December 2012. Detailed instructions will be contained in the prequalification documents.
Requests for prequalification documents and all questions relating to this Invitation to Prequalify shall be forwarded to the Engineer, MWH, at:
MWH Inc.
175 West Jackson Boulevard
Suite 1900
Chicago, IL 60604
Attn: David Walters, Bid Phase Administrator
Telephone: 1-312-831-3433
Email: david.a.walters@mwhglobal.com
This invitation to prequalify is intended for general contractors interested in performing all the work described herein. Potential suppliers and subcontractors desiring to receive a list of prequalified bidders (once it is available) should email Mr. Walters with their full contact information and a brief description of the goods and services they offer.
