The transport and mixing characteristics within the shallow environments studied vary considerably. This variance depends on:

the magnitude of the tidal forcing:

• strong tidal forcing
  • Suisun Bay
  • Sherman Lake
• to weak tidal forcing
  • Franks Tract
  • Mildred Island

and the physical configuration of the openings:

• multiple breach systems
  • Sherman Lake
  • Franks Tract
• and primarily a single breach system
  • Mildred Island.

In the strongly tidally affected areas, tidal excursions are long (7.5 miles) and residence times are short (less than a day). The residence times or exchange rates within all the shallow areas were significantly modulated by the spring/neap tidal cycle.

Finally, Sherman Lake represents a significant conveyance (on the order of Threemile Slough) between the Sacramento and San Joaquin River systems. Because the tide takes 60 minutes longer to reach the San Joaquin River side of Sherman Lake than it does to reach the Sacramento River side, a significant exchange is tidally pumped from the Sacramento River to the San Joaquin River that does not depend on the net flows (pumping or exports, Qwest, etc.).