cesspools in Yonkers had leaked sewage into Tibbetts Brook, which fed into the lake. A 1903 annual report from the New York City Department of Parks and Recreation mentioned that the lake had probably not been cleaned since the mid-18th century, and now contained a layer of "refuse and vegetation on top, and an ooze two to three feet deep on the bottom," with qualities more like a "semi-bog." Cleaning of the lake started in 1903. The lake's original earthen dam was removed, the lake was emptied, and of deposits were dredged from the lake bed. A new retaining wall was then erected along the lake's eastern shore, and a new dam was installed to reform the lake and to allow future cleaning of the lake without having to dredge it. After the opening of an overflow drain in 1911–1912, which connected to the sewer under Broadway completed in 1907, Tibbetts Brook was directed into the new sewer, The construction of the Van Cortlandt Golf Course compounded the lake's dirty condition, and by 1912, the lake and brook contained significant sedimentation. Nearby residents also disliked the wetlands near the lake, as they could be used to breed malaria-borne mosquitoes, and were thus seen as "unsightly and unsanitary." In 1896, they proposed to fill the wetlands in, and the infill proposal was funded by the New York City Board of Estimate in 1899. Subsequently, the Parks Department proposed to dredge the swamp and create a lake in its stead, but despite this plan receiving $70,000 in funding in 1906, it was deemed "not feasible" to drain the swamp directly into the Broadway sewer. Another plan to remove the swamps in the park's southwest was approved in 1904. The plan was to build an athletic field in the southwest swamp's place, but all swamp-infill proposals for this sector were rejected in 1917. By 1922, there were of swampland left in the park, and the Parks Department hoped to convert parts of it for some athletic purpose, but this required the New York Central Railroad to raise one of its bridges first so the swampland could be accessed. However, there are no records of that bridge being raised or of the swamp being converted. In its early years, the lake was used for boating, canoeing, curling, and ice skating. By 1899, the lake was used by up to 3,000 skaters on weekdays and