Much like the surrounding forests, the lakes and streams are essential components of Yaddo’s pastoral landscape. Similar to other lakes and ponds around Saratoga Springs, the Yaddo lakes were carved out by retreating glaciers. In 1932, the Corporation of Yaddo named the four lakes after the four Trask children who died in infancy and childhood. From east to west, the lakes are named Alan, Christina, Spencer, and Katrina. Just like he enhanced the landscape through reforestation and the selective placement of interesting looking rocks, Spencer Trask also altered the lakes. Originally, Lake Alan and Lake Christina were one lake known as Barhyte’s Lake. Historically, the stream from Barhyte’s Lake supplied water to two mills. There was a bridge and dam over the narrowest part of the lake. Spencer replaced the bridge with a causeway, dividing the lake in two. Lake Spencer and Lake Katrina were two small trout ponds. Spencer had the ponds dug out and dammed to enlarge the lakes and create waterfalls between each lake.
Unlike earlier landowners who used the lakes for economic purposes, Spencer made the lakes into a largely recreational space. He constructed scenic carriage drives and walks around the four lakes for the enjoyment of the family and their guests. He lined the carriage drives with stones from the same quarry as those in the Rock Garden. The Trasks also stocked the lakes with goldfish, similar to the ponds in the gardens. Spencer constructed a romantic-looking stone tower between Lake Katrina and Lake Spencer for use as an ice house, but the structure proved unsuitable for keeping ice frozen. They used the tower as a chapel until their deaths, when it became a studio for composers. Spencer also built a small wooden boathouse on Lake Alan to house a small rowboat and a pair of swans. By 1933, the boat and swans had to be removed because members of the public visiting the gardens were evidently causing problems out on the lake.
In 1932, Grounds Superintendent John Peterson engineered the Peterson Cascades. A stream draining from the Saratoga Race Course into Lake Spencer deposited a lot of silt. Peterson designed a series of three dams at different heights with basins to collect the silt. Peterson’s engineering project resulted in a series of picturesque waterfalls in the Yaddo forest. Artists in residence enjoyed walking to the Peterson Cascades through the wooded paths around the lakes.