The Massive 5-Million-Gallon Water Tank You Will Never See

San Diego hiking enthusiasts might have to share part of their favorite trail with a cement mixer for the next year. The San Diego County Water Authority is building a massive 5-million-gallon concrete water storage tank, called a flow regulatory structure. You will never see it once it’s completed.

One of the hiking trails in the northwest corner of Mission Trails Regional Park is closed and there are trail detours on other parts.