Tiber Creek or Tyber Creek, originally named Goose Creek, is a tributary of the Potomac River in Washington, D.C. It was a free-flowing creek until 1815, when it was channeled to become part of the Washington City Canal. Presently, it flows under the city in tunnels, including under Constitution Avenue NW. History Originally named Goose Creek, it was renamed during the late 1600s by settler Francis Pope, who owned a farmstead along the banks of the creek. Dubbing his land "Rome", Pope renamed the creek after the Italian city's river. Using the original Tiber Creek for commercial purposes was part of Pierre (Peter) Charles L'Enfant's 1791 "Plan of the city intended for the permanent seat of the government of the United States . . .". The idea was that the creek could be widened and channeled into a canal to the Potomac. By 1815 the western portion of the creek became part of the Washington City Canal, running along what is now Constitution Avenue. By the 1840s, when Washington had no separate storm drain and sewer system, the Washington City Canal had become a notorious open sewer. When Alexander "Boss" Shepherd joined the D.C. Board of Public Works in 1871, he and the Board engaged in a massive, albeit uneven, series of infrastructure improvements, including grading and paving streets, planting trees, installing sewers and laying out parks. One of these projects enclosed Tiber Creek and the Washington City Canal. A German immigrant engineer named Adolf Cluss, also on the Board, is credited with constructing a tunnel from Capitol Hill to the Potomac "wide enough for a bus to drive through to put Tiber Creek underground." Many of the buildings on the north side of Constitution Avenue apparently are built on top of the creek, including the Internal Revenue Service Building (IRS), part of which is built on wooden piers sunk into the wet ground along the creek course. The low-lying topography there contributed to the flooding of the National Archives Building (Archives I in Washington, D.C.), IRS headquarters, and William Jefferson Clinton Federal Building that forced their temporary closure beginning in late June 2006. Until the mid-1990s, land near the intersection of 14th Street and Constitution Avenue was a parking lot because the underground water was too difficult to deal with. During construction of the Ronald Reagan Building (1990–98), the engineers diverted the water. The dewatering then reduced the water