Large WSSC Water Mains May Impact Development

April 11, 2011

On February 4, 2011, the WSSC published a proposed amendment to its Pipeline Design Manual. The proposed change could have a significant impact on the development or redevelopment of any property which abuts or has running through it large diameter (in excess of 36 inches) water mains made of pre-stressed concrete cylinder pipe or cast iron pipe. The WSSC, in recent years, has expressed concern that water mains made of these materials could have catastrophic failures which could cause potential structural damage and personal injury. Accordingly, the proposed amendment would add the following sentence to the Design Manual, "A minimum horizontal separation of eighty (80) feet from a building or dwelling is required." Typically these high pressure water mains are located in rights-of-way which have been acquired by the WSSC and are approximately 50 feet in total width.

Notwithstanding the fact that the WSSC right-of-way may only be 50 feet in width, this proposed Design Manual change would purport to control the placement of structures well beyond the 50 foot right-of-way. The proposed Design Manual changes further state that if the property owner seeks to propose a separation of less than the required 80 feet, the landowner must, at its expense, propose structural enhancements and other alternatives which would protect abutting properties from a potential pipeline failure.

For security reasons, the WSSC is not allowed to publish a map showing the location of the pipe lines in question. These pipe lines crisscross much of Montgomery and Prince George's Counties. Accordingly, if you are a landowner with an interest in developing or redeveloping your property and are concerned about the proximity of your property to one or more of these water mains please feel free to contact us.