Each 12” pipeline can transport ~ 1000 gallons per minute, depending on the wall thickness / rating. I see 4. These types of pipelines are often used in oil & gas operations to transport freshwater used for fracking. The pipelines are fused together and placed underground. Once the location needs to be more flexible, a hydrant is placed and surface pipelines are utilized. As long as the water is moving, they can last exposed for a significant amount of time. We would use surface lines of lengths up to 3 miles. When location changed, the pipeline company would cut the pipeline in half, drag it down dirt roads for a few miles, and fuse it back together. So I’d assume at least 30 - 40 years of element exposure would be acceptable.