Bull Lake Dam modifications consist of constructing a temporary cofferdam, excavation, for a new spillway and stilling basing, and removal of the existing spillway.  The owner of this project is the Bureau of Reclamation, Great Plains Division and the General Contractor is Malcolm International.

For the excavation of the new spillway, a design-build dewatering system was required Malcolm Drilling contracted GeoEngineers out of Redmond WA for not only the pre-bid design but for the submitted eductor design.  The design-build dewatering system consists of a combination of eductor wells and deep small diameter wells that can be converted to either eductor wells or vacuum assist wells at a later date. Dewatering maintenance is required 24/7 during the running of the dewatering system that includes a 100 HP supply pump with dual header pipes, one 6in providing water to the wells and one 8in returning water to the pump.  Malcolm Drilling installed all the 96 wells using a sonic drill rig to ensure that air was not used for spoil extraction. Wells depths ranged from 55ft to 90ft in-depth depending on the location on the dam. Dewatering will pull and maintain a water level approximately 35ft below static water levels.

If you would like to learn more about this project, please contact

Matt Kennedy – MKENNEDY@malcolmdrilling.com