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NoVA & DC Plumbing Map

Sheet 1 of 18 · District of Columbia

Capitol Hill plumbing, mapped for owners

Full map

On Capitol Hill, DC Water handles the water and sewer mains and public-space service lines, while you own the private pipes and the lateral, and the DC Department of Buildings issues the permits.

Sheet revised November 3, 2026 · who makes this map

Painted rowhouses on Capitol Hill with parked cars in front
Rowhouses on Capitol Hill.
Who does what here
WaterDC Water, up to the property line or approved projection; you own the rest source
SewerDC Water owns the main; the lateral is yours to maintain source
PermitsDC Department of Buildings, with a named master plumber source
LicensingDLCP Board of Industrial Trades source
Lead pipesDC Water lead map and Lead Free DC source

What is particular to Capitol Hill

This sheet is about rowhouse-block plumbing: long runs of attached buildings. We do not have a source that dates any Capitol Hill block, so we do not guess at pipe age. What we can say is how the rules read for an attached house.

Review comes first. DC's Historic Preservation Office reviews work when a building permit is needed and the work affects the exterior. Installing plumbing equipment counts as an alteration under those rules, while a vent that cannot be seen from the street is treated as minor. Interiors are reviewed only where they are designated. Find out from that office whether your address lies in a district before you book work that changes a roof, wall or front.

Brick rowhouse steps and iron railings under street trees on Capitol Hill
Front steps and railings on a tree-lined Capitol Hill block.

Old drain stacks in attached houses

A cast-iron stack in a rowhouse often serves more than one floor. A repair can mean opening walls, and that is a licensed master plumber's work under a DC permit. See cast-iron drains for what we can and can't say about them.

If an old cast-iron stack is repaired, your plumber may name couplings like these: no-hub fittings at PlumbingSupplyAndMore (that store has the same owners as this map).

Backups and the combined sewer

DC Water says about one-third of the District is on a combined sewer, and backups are more common there. Which pipe serves your block is a question for DC Water, not for this map. When a drain backs up, stop using water, keep children and pets clear of the sewage, and phone DC Water at 202-612-3400. A backwater valve may qualify for a rebate of up to $6,000 where the owner has a documented backup, and the rebate office is 202-787-2003. The work needs a permit pulled by a DC-licensed master plumber. Details are on backwater valves.

Trees and the curb

Street trees on a block of rowhouses sit close to laterals. Roots are one of the causes DC Water lists for lateral failure; see street trees and roots.

What the map can't tell you

  • Which blocks are inside a historic district, and what that means for a given repair.
  • Whether your sewer is combined or separate.
  • Whether a party-wall stack is shared with a neighbor; the deed and a licensed plumber can say.
  • Whether your service line has lead; DC Water's map is mostly historic records, not confirmed.

Check your own address

  1. Open DC Water's lead map and look up your address, then read what color it shows and what the key says it means.
  2. Call DC Water on 202-612-3400 to ask which sewer serves your street.
  3. Phone the Historic Preservation Office about your address before applying to DOB.
  4. Look up the plumber's license on the DLCP site and make sure the permit names that person.
  5. Call 811 before anyone digs outside; if unsure, call a licensed pro.

More on checking an address

Survey notes: sources for this page