On April 25th, 2012, the Marin Municipal Water District celebrated their 100 year anniversary as the State of California’s first municipal water district. MMWD has been shaped by significant historical events, but the one that has influenced the County and CSW|ST2 the most has been Dietrich Stroeh’s involvement as the District Manager during the water crisis of 1976 and 1977. Marin County went for 25 months without rain and with Diet’s leadership and direction Marin went from near disintegration to the development of infrastructure that has served the County for the past thirty-five years. Diet has captured this pivotal moment in history in his book The Man Who Made it Rain.
Have we learned our lesson though? Even in the Bay Area are we as conscious about our water use as we should be? MMWD has been very proactive in developing conservation techniques and regulations for commercial, residential, and public projects to ensure that we have water for the future. But it is up to us at CSW|ST2 as engineers and planners to be conscious of the way we design for our clients, innovative in specifying new technology, and to be sensitive to the existing natural resources that we all want to preserve.
Congratulations MMWD and we look forward to the next 100 years!
“We have been quick to assume rights to use water but slow to recognize obligations to preserve and protect it…”
-Sandra Postel, “Last Oasis: Facing Water Scarcity”
(Completed San Quentin Storm Water Pump Repair)
CSW|ST2 recently completed a rehabilitation of the San Quentin Pump Station in San Rafael so we thought we’d show you how we get down and dirty…. and the best part is that we like it! The San Quentin Storm Water Pump Station was originally built from 1973-74 as part of the East San Rafael Drainage Assessment District. It was modified in 1997 with the addition of a 60” HDPE discharge line to handle the increase in storm water runoff in the Assessment District. Between 1997 and 2011 the pipeline has experienced settlement which has developed into operational problems with the station. Portions of the existing 60” HDPE discharge pipe had pulled away from the station wall approximately 4 1/2”, creating problems during the start-up phase, one of which was discharging water through the opening and eroding the surface and roadway.
(Contractor lowering 8.5 LF, 60″ stainless steel pipe in place)
The design developed by CSW|ST2 was divided into two approaches; the first solution was to remove 9 LF of the existing 60” HDPE and replace it with a fabricated 8.5 LF, 60” stainless steel pipe to be secured to the existing 60” HDPE discharge line with a fabricated stainless steel band. In the picture above you can see the contractors lowering the new 60″ pipe into place.
(Contractors moving new 60″ flanged, 4 LF spool into the pressure chamber)
The second solution was to fabricate a 60″ flanged, 4 LF stainless steel spool and lower it into the pressure chamber and install it into the discharge opening. The picture above shows the spool being moved into position by the crane.
(Raising the pressure chamber)
The final element of the station’s partial rehabilitation involved raising the pressure chamber. Raising the pressure chamber benefited the station for the following reasons:
- Raising the pressure chamber and adding a relief line reduced the pressure at start-up and put less pressure on the connection. For security reasons the discharge piping (8”+/-) was routed in such way as to avoid entrance to the station by climbing on top of the pipe.
- Removing the top of the concrete pressure chamber allowed the contractor to lower a flanged sleeve.
- The existing pressure chamber was damaged therefore it was necessary to repair it for structural integrity.
The project was completed in 15 days bringing us in on time and within our budget. So, not only can CSW|ST2 get down and dirty but we do it pretty efficiently as well!