Why the Renewal of the El Granada Pipeline Must be a 16-inch gravity flow pipeline

By Jim Larimer

The required diameter of the El Granada pipeline is determined by the laws of physics and should not be allowed to become a political issue decided by individuals who want to slow or stop growth in our community. The physics determine fire safety, not community politics.

In the past 55 years the number of water hook ups served by the CCWD has increased from around 300 in the late 1940's to over 6,000 today. The El Granada area has grown into a large and beautiful wooded community during this period. Many homes have been built in this area and in the wooded hills. The security of these homes relies upon an adequate supply of water and water pressure to put out fires should they occur.

In the last 55 years the California standards for water pressure and water flow rates from fire hydrants has substantially increased. California law does not require immediate improvements to infrastructure in areas that become substandard when a new higher standard is enacted. These areas are brought up to the modern standard as the infrastructure in an area is renewed through the standard repair and replacement of pipelines and fire hydrants over time.

There are two components of the fire flow standard, the volume of water provided at a hydrant, and the pressure at which this water is delivered. Both are vital to the ability of the hydrant to deliver adequate water to put out fires. Increasing the diameter of the El Granada pipeline will increase the pressure at hydrants without pumping. A 16-inch gravity flow replacement means that we can replace the old El Granada pipeline and retire a permanent pump and the emergency pump that are now required to satisfy demand. The larger diameter pipe will also deliver higher water pressures bringing many areas in El Granada up to today's fire safety standard.

A 16-inch diameter gravity flow replacement will also be better able to support future needed improvements to areas that will remain below the fire flow and pressure standards. These community areas also need to be enhanced and will be as the normal capital improvement, i.e., repair and replacement of old worn out infrastructure, proceeds in future years.

The required diameter of the pipeline is determined by the laws of physics and should not be allowed to become a political issue decided by individuals who want to slow or stop growth in our community. The physics determine fire safety, not community politics. Water when it moves through a pipe rubs against the pipe walls and this results in a friction loss in water pressure at the exit end of the pipe. The smaller the pipe and the longer the pipe together produce more friction and therefore a greater pressure loss at the exit end of the pipe. To achieve the pressure we need for fire safety we need a larger diameter pipe. This is a straightforward law of nature and why we need a larger diameter pipe.