ASHINGTON, April 28 — In the latest state-versus-state battle over water rights to reach the Supreme Court, the justices agreed today to decide whether Virginia needs Maryland's permission to draw water from the Potomac River, which forms part of the boundary between the two.

A special master appointed by the court more than two years ago to resolve this chapter of a dispute that dates from the 18th century supported Virginia in a report to the justices late last year. Maryland objected, and the justices announced today that they would hear arguments and decide the matter themselves in the court's next term.

There is no dispute that Maryland owns the river under a land grant from King Charles I to Lord Baltimore in 1632. At issue are the regulatory rights that come with ownership, and it has been evident for centuries that King Charles did not have the last word. The two states entered into a compact in 1785 that gave each the right to fish and "the privilege of making and carrying out wharfs and other improvements" as long as navigation was not obstructed. Arbitration in 1877, approved by Congress in 1879, placed the interstate boundary at the low-water mark on the Virginia side.

The current dispute began with a 1996 plan by Fairfax County, a fast-growing area on the Virginia side, to replace an old intake pipe with a longer one extending 725 feet into the 2,000-foot-wide river, in order to avoid the muddy water nearer the shore. Maryland maintained that the Fairfax County Water Authority needed a permit, which it then refused to issue.

After losing administrative and state court rulings, Maryland yielded and the pipe was built. Virginia pursued the matter by filing a case directly in the Supreme Court to establish its future rights to withdraw water without Maryland's permission. Maryland responded by seeking a broad declaration of its right to control all activities taking place "in the bed and waters of the Potomac River" up to the low-water mark on the Virginia side.

The case, Virginia v. Maryland, No. 129 Original, has become a symbol of the struggle to control growth and natural resources in a region where the political culture has been one of competition rather than cooperation.

After accepting 25 volumes of historical documents and other material, the special master, Ralph I. Lancaster, a lawyer from Portland, Me., urged the two states to settle their problems amicably through mediation.

But five months of closed-door mediation failed, and Mr. Lancaster made his formal recommendation to the justices in December, rejecting Maryland's position and urging the justices to "enter judgment declaring that Virginia and its citizens have the right, free of regulation by Maryland, to construct improvements in the Potomac appurtenant to the Virginia shore and to withdraw water from the Potomac." He based his decision on several pieces of historical evidence, including a Supreme Court decision in 1910 that recognized Virginia's independent rights to the Potomac.

Under the Supreme Court's so-called original jurisdiction to hear disputes between states, the justices can adopt a special master's recommendations or permit the states to make further arguments. Maryland argued in its appeal, known technically as "exceptions to the report of the special master," that "the river belongs to Maryland and is subject to Maryland's sovereign and regulatory authority." Maryland said Virginia had long acquiesced to that understanding.

Virginia argued in response that it had objected since 1976 to Maryland's insistence on its right to review requests to withdraw water, but that the issue had not been joined until this dispute because Maryland had previously always granted the permission that Virginia sought. Fairfax County had received a series of approvals from Maryland to increase withdrawals from the river, which now provides about half the county's water supply. Because of a surging population, Virginia's demands on the river have grown faster than those of Maryland, and the river itself is under increasing pressure from withdrawals that now average 400 million gallons a day, up 19 percent from those of 10 years ago.

While "original" cases are a staple of the court's docket, few attain high visibility outside their local regions. The most famous recent case was the dispute between New York and New Jersey over Ellis Island, in which New Jersey prevailed.

As local residents, all the justices may have more than a passing interest in the new case. Of the court's nine members, five live in the Virginia suburbs: Chief Justice William H. Rehnquist and Justices John Paul Stevens, Antonin Scalia, Anthony M. Kennedy and Clarence Thomas. Three, Justices Ruth Bader Ginsburg, Stephen G. Breyer and David H. Souter, live in the District of Columbia. Only Justice Sandra Day O'Connor lives in Maryland.

These were among the other developments at the court today:

Abortion Regulations

Without comment, the court turned down a challenge by a South Carolina abortion clinic to several of the state's licensing requirements for such clinics. Among other provisions, the Greenville Women's Clinic objected to a requirement that state health officials be given access to patients' individual records, as well as to a requirement that a member of the clergy be on call for consultation with patients. The United States Court of Appeals for the Fourth Circuit, in Richmond, Va., rejected the clinic's challenge to the 1995 law that laid out the requirements.

In its appeal, Greenville Women's Clinic v. Commissioner, No. 02-1235, the clinic argued that the access provision violated patients' right to privacy and that the clergy requirement was an unconstitutional endorsement of religion. In its response on the clergy issue, the state said it was "quite sensible" in light of "the fact that to many female believers, the potential impact of the abortion transcends secular psychology and may well have ramifications for her `immortal soul.' "

Ten Commandments

Also without comment, the court refused to hear an appeal by the State of Kentucky of a ruling that the state's plan to erect a six-foot Ten Commandments monument on the State Capitol grounds in Frankfort lacked a valid secular purpose and was unconstitutional. Ten other states urged the justices to review the ruling, issued last October by the United States Court of Appeals for the Sixth Circuit, in Cincinnati.

There has recently been a new wave of such Ten Commandments disputes around the country, but because every court to consider the cases has ruled against display of the monuments, there is as yet no conflict of the sort the Supreme Court ordinarily requires before taking up an issue. This case was Russ v. Adland, No. 02-1241.