What is the test for establishing that the lowest water level should be the boundary of a lake?

4 We also reject appellant's claim that the lowest water level should be decreed to be the boundary, so as to insure that littoral owners have access to the lake at all times. First, there is certainly no evidence that sovereign entities ever sought to prevent appellant or any other littoral owners from enjoying access to the water. Second, appellant and other owners are protected from such an attempt to block their access to the water, since they share in the access rights which all citizens enjoy by virtue of the public trust doctrine. (See State of California v. Superior Court (Lyon), supra, 29 Cal.3d at pp. 226-233, 172 Cal.Rptr. 696, 625 P.2d 239.)