Who Owns the Potomac? (Part 2)

Michael Nardolilli is the Executive Director of the Interstate Commission on the Potomac River Basin. The opinions expressed are those of the author and should not be construed as representing the opinions or policies of the United States or any of its agencies, the Interstate Commission on the Potomac River Basin or any of its Commissioners, or any of the jurisdictions in the Potomac River Basin.

Washingtonians may wonder why Theodore Roosevelt Island and Columbia Island are located within the District of Columbia while Gravelly Point and Reagan National Airport are in Virginia. As we will see below, the boundary line between Virginia and the District of Columbia north of Jones Point and south of Little Falls along the Potomac River is a little muddied, both figuratively and literally.

Last year, I posted the first part of this series and discussed the boundary line between Virginia and Maryland along the Potomac River south of Jones Point in Alexandria, VA.  To summarize Part 1, Maryland argued that its charter ran to the tidal high-water mark on the Virginia side of the river. Nonetheless, the Black-Jenkins Arbitration Award of 1877 established the boundary between Virginia and Maryland south of Jones Point to be the low-water mark along the Virginia shoreline because Virginia had prescriptive rights (through long historical usage) down to the low-water mark. The arbitrators also determined that the line would run “from low-water mark at one headland to low-water mark at another, without following indentations, bays, creeks, inlets or affluent rivers.” The Black-Jenkins Award was approved by the U.S. Congress in 1879. The Matthews-Nelson Survey of 1928 determined that the boundary would follow the curving low-water mark of the Virginia shoreline south of Jones Point in Alexandria to Smith’s Point at the mouth of the Potomac except for tangents where the boundary would consist of a straight-line between specific headlands. The Virginia-Maryland Boundary Commission placed 58 Boundary Monuments at each of these points to mark forever the boundary line between the two states and this Survey was confirmed in the Potomac River Compact of 1958.

Unfortunately, these simple rules do not apply north of Jones Point because of the creation of the District of Columbia, the Act of Retrocession, and the muddy Potomac itself.

With the establishment of the original 10-mile square District of Columbia, the federal district encompassed both shorelines of the Potomac River as well as the riverbed underneath. When the federal government “retroceded” the Virginia portion of DC back to Virginia in 1847, a dispute arose as to whether DC would be allowed to claim that its prior ownership of the entire riverbank entitled it to use the high-water mark on the Virginia side as the proper boundary. A series of Supreme Court cases determined that Virginia’s prescriptive rights against Maryland --- the basis of the Black-Jenkins Award --- did not apply to the District of Columbia. Accordingly, the rule for the boundary north of Jones Point and south of Little Falls (the limits of the tidal Potomac) would be the high-water mark along the Virginia shoreline.

But silt coming down the muddy Potomac River constantly changes the shoreline along its banks as well as the islands in the river itself. And dredging operations have moved some of that silt to create new islands and push other lands further into the river. How would those natural and man-made forces influence the boundary line?

Theodore Roosevelt Island (previously known as Analostan or Mason’s Island) had been granted to Maryland and then transferred to DC in 1791. The construction of a man-made causeway over the “Little River” between the Virginia shore and the island cut off the flow of water into the Little River and resulted in the sudden buildup of silt and mudflats where there was once open water. Despite these new “land” connections to the Virginia shore, however, the island remained in the District of Columbia for a variety of reasons. For example, a long-running ferry (and briefly, a pontoon bridge) connected the island to Georgetown in the District of Columbia, the Mason family (prominent Virginian aristocrats) sold their island prior to retrocession and the Union Army occupied the island during the Civil War. In any event, the causeway was removed and today the Little River once again flows between Theodore Roosevelt Island and the Virginia shoreline.  

Further downstream, the narrow channel between Alexander’s Island and the Virginia shoreline began to silt up gradually due to natural forces. Once part of DC, after 1870 the area became known as Jackson City, a lawless haven for gamblers. When Virginia officials began to crack down on the gambling there, the District of Columbia had little incentive to dispute the enforcement of Virginia law on what appeared to be more of an unruly extension of the Virginia shoreline rather than a true island.

Columbia Island, now found between Roosevelt Island and Alexander’s Island, was once nothing but mudflats that were part of the District of Columbia. Over time, some dredge spoils from the river bottom, plus some fill dirt from construction projects in the District and solid rock from the shipping channels, were dumped in the marshes along the Virginia shoreline. The transformation of piled up dredge spoils to today’s Columbia Island was completed as part of the Arlington Memorial Bridge Project. To ensure floodwaters could pass on either side of the bridge piers, engineers created wider gaps between Columbia Island and Roosevelt Island as well as the aptly named Boundary Channel between Columbia Island and the Virginia shoreline. Was this new island in Virginia?

Meanwhile in Alexandria, landowners had extended their property and piers far out into the river. The Corps of Engineers had defined a "pierhead" line on the Alexandria stretch of riverfront in 1939, surveying the edge of waterfront improvements and how far the piers and docks extended into the river. How did that affect the boundary?

Similarly, what is now Reagan National Airport was built near Gravelly Point on mudflats that were once within the District of Columbia. Dredged materials converted a portion of the Potomac River channel into dry land. A location that had been below the low-water mark became dry land above the high-water mark. Was this part of Virginia or still within the District of Columbia? 

Under the Constitution, Congress has broad powers to determine the boundaries of the District of Columbia so it is not surprising that these disputes were settled by Congressional action. Public Law 208, 59 Stat. 552 (1945) carefully drew the snaking boundary line between DC and Virginia as follows:

“Said boundary line shall begin at a point where the northwest boundary of the District of Columbia intercepts the high-water mark on the Virginia shore of the Potomac River and following the present mean high-water mark; thence in a southeasterly direction along the Virginia shore of the Potomac River to Little River, along the Virginia shore of Little River to Boundary Channel, along the Virginia side of Boundary Channel to the main body of the Potomac River, along the Virginia side of the Potomac River across the mouths of all tributaries affected by the tides of the river to Second Street, Alexandria, Virginia, from Second Street to the present established pierhead line, and following said pierhead line to its connection with the District of Columbia-Maryland boundary line; that whenever said mean high-water mark on the Virginia shore is altered by artificial fills and excavations made by the United States, or by alluvion or erosion, then the boundary shall follow the new mean high-water mark on the Virginia shore as altered, or whenever the location of the pierhead line along the Alexandria water front is altered, then the boundary shall follow the new location of the pierhead line.”

Today, while issues do arise from time-to-time (e.g., the Old Dominion Boat Club in Alexandria), the 1945 Act still sets the boundaries along this section of the Potomac River.

Finally, neither Part 1 nor Part 2 of this series addressed these two issues: (1) usage of the Potomac River (water, oysters, structures, etc.); and (2) whether the state boundaries along the Potomac change over time through the river forces of accretion, erosion, reliction and avulsion. The usage issue is beyond the narrow scope of this series. The change issue, as well as the boundary line from Little Falls to Harper’s Ferry, will be discussed in Part 3.    

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