Hurricanes Harvey and Irma have certainly been a test for infrastructure, and while flooding seems inevitable under such extreme conditions, there are valuable lessons to be learned from these two storms.
The biggest concern for people outside the affected area following Hurricane Harvey’s assault on the Houston area was the disruption in supply of gasoline and resulting high prices. Approximately one-sixth of total pipeline mileage in the U.S. is in Texas. Many of those pipelines start or end on the Gulf Coast, where about 35 major refineries are located.
At one point, refineries that produce more than 2 million barrels per day of gasoline were taken out of service in the area. While some refineries were up and operating quickly, production was still much lower than normal so there was not enough refined product being created to push product through the system. The same held true for crude oil being pushed through the pipelines to the refineries.
While pumps and valves at the start of a pipeline get crude or refined product moving, momentum or operating pressure is needed to keep it moving through the pipes to the other end where the pumps suck it out. Pipeline operators can reduce pressures to accommodate lower flows, but the types of pumps and valves in the line will determine how low the flow can be before it stops. Some systems can operate at pressures as low as 20%, but that is not the norm.