WATER TRANSMISSION
Raw Water Transmission Line Replacement
Morrison, CO
Our engineers prepared a Water Supply System Master Plan for the Town of Morrison, which outlined water system improvements necessary to meet the Town’s future water needs. These improvements included the replacement of a raw water transmission line and grit chamber along Bear Creek – identified in the master plan as one of the most critical areas in need of pipe replacement.
The former transmission pipeline was completely buried, except for the portion located inside a tunnel. In time, rock movement around the buried pipe caused the pipe along the canyon wall to become unstable. In order to avoid these rock slide problems and add further structural integrity to the pipe, this portion of the new transmission line was to be installed above ground (approximately 180 ft.). Additionally, the high-density polyethylene (HDPE) pipe was housed inside a steel pipe casing, which both increased the strength of this structure and insulated the pipe to keep the water from freezing. The enhanced integrity of this new structure allowed the Town to replace the 10-inch pipe with a 16-inch pipe, greatly increasing its capacity.
Construction along this difficult terrain was accomplished by transporting the construction materials down Bear Creek. The design included numerous concrete supports that were anchored into rock along the canyon wall. Hence, the steel pipe casing was transported down the creek and carefully installed on the concrete supports; once this was in place, the polyethylene pipe was inserted into the casing.
75th Street Diversion and Pipeline
Lafayette, CO
The City had been working diligently to obtain a new diversion location for their water rights from Boulder Creek. After many long years, negotiations with the City of Boulder grew more favorable for the new diversion location as long as a fast track solution could be presented and agreed upon. On the heels of the worst drought in Colorado in the last 50 years, MWE personnel were retained by the City for preliminary design, project planning, final design, permit negotiations, development of construction plans and specifications and construction project management for the 75th Street Diversion and Pipeline project. The grouted boulder drop structure/diversion incorporated multiple uses, including fish passage through a previously barricaded reach of Boulder Creek, a design for safe recreational use, and significant re-vegetation due its location within City of Boulder Open Space property.
The project also included 5 miles of 36-inch gravity pipe, a grit removal chamber, meter vault and an outlet structure into the Goose Haven reservoir complex. The pipeline route required a railroad crossing, deep excavation, microtunneling, wetlands mitigation, constant de-watering, endangered species protection and the simultaneous coordination of several pipeline contractors. The planning phase included permit preparation for crossing under the railroad, a floodplain development permit, USACE 404 Permit, a 401 Water Quality Certification, and a Boulder County 1041 permit. The diversion and pipeline were constructed in the short time frame required, completed in 2003, satisfying both the City of Lafayette’s raw water needs and the City of Boulder’s and Boulder County’s permit requirements.