Even in a "pitiful" tidal swing, creative engineering can bottleneck enough water to create tremendous force.Most So Cal tides are pitiful. The northern stretches of Sea of Cortez have tide swings of at least 6 feet and sometimes more than 20 feet depending on the phase of the moon. Land is cheap and there are big markets for power in easy reach. Tides are predictable, plus or minus wind and rain effects, and sometimes the maximum power available occurs during peak demand times.
http://sanfelipe.com.mx/weather/tide-calendars/