The first question for decision here is whether plaintiff’s lots, or any portion thereof, were “taken” by the Town of Carolina Beach for the construction of the berm erected to control tidal erosion. Resolution of this problem requires a discussion of the general principles of ownership applicable to tidal lands.
 It has been settled since the passage of the Submerged Lands Act of 1953 by the United States Congress that the lands beneath coastal waters belong to the states, and not the federal government. “The seaward boundary of each original coastal state is approved and confirmed as a line three geographical miles distant from its coast line. . . . Nothing in this section is to be construed as questioning or in any manner prejudicing the existence of any State’s seaward boundary beyond three geographical miles if it was so provided by its constitution or laws prior to or at the time such State became a member of the Union, or if it has been heretofore approved by Congress.” 43 U.S.C. § 1312; 67 Stat. 31; Bruton v. Enterprises, Inc., 273 N.C. 399, 160 S.E. 2d 482 (1968); Capune v. Robbins, 273 N.C. 581, 160 S.E. 2d 881 (1968). This concession is subject to specific reservations for use of such waters for navigation, flood control, or the production of power by the federal government. 43 U.S.C. § 1311; 67 Stat. 30. The authority of the State is further restricted by the Commerce Clause of the United States Constitution. “[T]he federal government, by virtue of its constitutional authority to regulate interstate and foreign commerce, has paramount power to control all navigable waters of the United States to the extent necessary for that purpose, and both the state and the riparian owners hold such waters and the lands under them subject to that power.” Annotation, Rights to land created at water’s edge by filling or dredging, 91 A.L.R. 2d 857 (1963). See generally, Aaron L. Shalowitz, Boundary Problems Raised by the Submerged Lands Act, 54 Colum. L. Rev. 1021 (1954). There is no ascertainable federal interest here, and we therefore direct our comments to the interests of the State and its property owners.
Where is the dividing line between the property of the State and that of the littoral private owner? There is a division among the States on that question, and the groups may be conveniently labeled “high-tide” states and “low-tide” states.
 The “strip of land between the high- and low-tide lines” is called the foreshore. 1 Powell on Real Property § 163; Capune *302 v. Robbins, supra (273 N.C. 581, 160 S.E. 2d 881). The high-tide states hold that private property ends at the high-water mark, and that the foreshore is the property of the state. The low-tide states, on the other hand, fix the boundary at the low-water mark, and the foreshore is said to belong to the littoral landowner unless it has been otherwise alienated. Powell on Real Property, supra; Annotation, supra, 91 A.L.R. 2d 857; 6 Thompson on Real Property § 3084 (1962); 56 Am. Jur., Waters § 458.
Although the North Carolina position is somewhat obscured by the vagaries of ancient cases, see David A. Rice, Estuarine Land of North Carolina: Legal Aspect of Ownership, Use and Control, 46 N.C.L. Rev. 779 (1968), North Carolina is a high-tide state. Under the old “entry and grant” statutes (which were replaced in 1959 by the State Land Act, Session Laws, 1959, c. 683, codified as Gen. Stat., c. 146), only land under non-navigable waters could be entered. Ownership which might interfere with navigation was not allowed. Therefore, littoral rights in ocean-front property did not include the title to the foreshore, which remained in the State. McKenzie’s Executors v. Hulet, 4 N.C. 613 (1817); Ward v. Willis, 51 N.C. 183 (1858); State v. Glen, 52 N.C. 321 (1859); Insurance Co. v. Parmele, 215 N.C. 63, 197 S.E. 714 (1938); Swan Island Club v. White, 114 F. Supp. 95 (E.D.N.C. 1953); Parmele v. Eaton, 240 N.C. 539, 83 S.E. 2d 93 (1954); Rice, supra, p. 805; Capune v. Robbins, supra.
The State Land Act of 1959, supra, carries forward the distinction between navigable and non-navigable waters and provides that land under navigable waters cannot be “conveyed in fee,” but that easements may be granted. G.S. 146-3. More importantly, the act creates a new subclassification for lands “which lie beneath . . . The Atlantic Ocean to a distance of three geographical miles seaward from the coastline of this State,” and provides that no such lands can be “conveyed in fee.” G.S. 146-3 and 146-64. There is nothing in the new act to change the general rule that ownership of the foreshore remains in the State. On the contrary, it is noteworthy that a special class was created for the protection of the foreshore and the marginal seas. We therefore adhere to our long established rule that littoral rights do not include ownership of the foreshore.
*303The littoral owner may, however, in exercise of his right of access, construct a pier in order to provide passage from the upland to the sea. “ ‘But the passage under the pier must be free and substantially unobstructed over the entire width of the foreshore. This means that from low to high water mark it must be at such a height that the public will have no difficulty in walking under it when the tide is low or in going under it in boats when the tide is high.’ ” Capune v. Robbins, supra. This language is consistent with the view we take here that the foreshore is reserved for the use of the public.
 Applying the foregoing principles, we hold that the seaward boundary of plaintiff’s lots is fixed at the high-water mark. The high-water mark is generally computed as a mean or average high-tide, and not as the extreme height of the water. People v. William Kent Estate Co., 242 Cal. App. 2d 156, 51 Cal. Rptr. 215 (1966); Borax Consolidated, Ltd. v. Los Angeles, 296 U.S. 10, 80 L. Ed. 9, 56 S. Ct. 23 (1935).
 Chapter 511 of the 1963 Session Laws relating to erosion control work in the Town of Carolina Beach was ratified 22 May 1963. Section 1 of the Act provides that so much of the lands to be filled in and restored which lie east of the “building line” (to be established as provided in said Act) is granted and conveyed in fee simple to the Town of Carolina Beach. Plaintiff’s Exhibit “U” is a map of the “building line” established by the Town along the ocean front pursuant to said Act. This map, offered in evidence by plaintiff, shows that in January 1964 Lots 1 through 10 of Block 216 were completely submerged and the mean high-water mark of the Atlantic Ocean was in approximately the center of Carolina Beach Avenue north. The building line at this point was accordingly established along the western margin of Carolina Beach Avenue north. Thus, twelve months before the berm was built, plaintiff’s lots had been taken by the sea and title thereto had vested in the State of North Carolina. This condition is confirmed by the following testimony of plaintiff’s principal stockholder and witness Sam H. Blake: “By the fall of 1963 I had to extend the entrance of the ramp across the western side of Carolina Beach Avenue, and that was because one would have had to walk through water to get to the ramp at times. That street is approximately 40 feet wide, and our extension was 40 feet to the west in the fall of 1963, which was because the water had moved up into the street, but not all the time.”
*304“It is a general rule that where the location of the margin or bed of a stream or other body of water which constitutes the boundary of a tract of land is gradually and imperceptibly changed or shifted by accretion, reliction, or erosion, the margin or bed of the stream or body, as so changed, remains the boundary line of the tract, which is extended or restricted accordingly. The owner of the riparian land thus . . . loses title to such portions as are so worn or washed away or encroached upon by the water.” 56 Am. Jur., Waters § 477; Jones v. Turlington, 243 N.C. 681, 92 S.E. 2d 75 (1956). Thus the lots of the plaintiff were gradually worn away by the churning of the ocean on the shore and thereby lost. Its title was divested by “the sledge-hammering seas . . . the inscrutable tides of God.” Herman Melville, Moby Dick.
[5, 6] G.S. 146-6, which governs the title to land raised from navigable waters, permits vesting of title to such lands in the littoral landowner (1) where he does the filling himself by permission of the State and under approved procedures or (2) where the purpose of the filling is “to reclaim lands theretofore lost to the owner by natural causes.” G.S. 146-6 (b), (c). Manifestly, the purpose here was the preservation and protection of the Town of Carolina Beach from the fury of the sea rather than the reclamation of the lands of private owners along the beach. Accordingly, we conclude that the purpose to be served by construction of the berm was not to reclaim lands theretofore lost to the owner by natural causes, and when Lots 1 through 6 and Lot 9 of Block 216 were raised above sea level by the sand berm title to the land so created which was located east of the building line vested in fee in the Town of Carolina Beach as provided in Chapter 511 of the 1963 Session Laws. This legislative grant to the Town of title to property east of the building line and extending to the low water mark of the Atlantic Ocean is inconsistent with G.S. 146-3(1). Even so, the 1963 Act repeals all laws in conflict with it and must be regarded as controlling in this instance. The Legislature has the power to abrogate, amend or make exceptions to its own acts. In this instance it has done so. Therefore, by virtue of Chapter 511 of the 1963 Session Laws, the Town of Carolina Beach owned the lots in question when the sand berm was built.
[7, 8] Plaintiff did not sue for damages to its fishing pier. Rather, plaintiff alleged that construction of the berm resulted in a total loss of the seven lots described in the complaint upon *305which was located a commercial fishing pier extending into the Atlantic Ocean approximately 900 feet from the mean high water mark. Plaintiff sought recovery of $41,000 as the fair market value of said property at the time it was allegedly taken by defendant for a public purpose. Such is the theory of plaintiff’s case, and it must be tried upon that theory. It cannot be submitted to the jury on a theory of liability not supported by allegation and evidence. Moody v. Kersey, 270 N.C. 614, 155 S.E. 2d 215 (1967); Calloway v. Wyatt, 246 N.C. 129, 97 S.E. 2d 881 (1957); Herring v. Creech, 241 N.C. 233, 84 S.E. 2d 886 (1954); Morgan v. Oil Company, 238 N.C. 185, 77 S.E. 2d 682 (1953). Plaintiff cannot avail itself of evidence contrary to the allegations of its complaint. Davis v. Rigsby, 261 N.C. 684, 136 S.E. 2d 33 (1964); Watson v. Clutts, 262 N.C. 153, 136 S.E. 2d 617 (1964); Faison v. Trucking Co., 266 N.C. 383, 146 S.E. 2d 450 (1966). Thus the trial court properly rejected plaintiff’s proffered evidence of the cost of a 180-foot extension to the fishing pier and the cost of replacing the ramp. That was not the theory of the case, and the complaint understandably contains no allegation which would render such evidence admissible. Had a taking been shown there was no competent evidence upon which the jury could have based its answer to the damages issue.
Plaintiff having failed to show either a taking or damages under applicable rules of law, the judgment of nonsuit is