Ketner Lake is located in southwest Westminster, within the city-owned, 57.4-acre Ketner Lake Open Space. Situated in the neighborhood north of the intersection of West 100th Avenue and Countryside Drive, the 21.5-acre lake is also found south of Witt Elementary School. Properties that surround Ketner Lake are developed with residences and the school, along with open prairie in the drainageway to the east.
Public access is gained from all directions and a one-mile trail offers visitors a walk around the lake’s perimeter and through the adjacent open space.
A 2,360 foot-long earthen dam on the eastern shore retains the lake, making it a water storage reservoir rather than a natural body of water. Wetlands and a cottonwood grove are found along the lake’s western shore.
Ketner Lake and its surrounding open space were acquired by the City of Westminster in 1987 from the Mandalay Irrigation Company, which by then was largely under the ownership of the City of Thornton.
This lake dates back to the very early 1900s, when it was known as Little Church Reservoir and was evidently associated with the area’s pioneer ranching and farming Church family. For many years it was fed by a spring located a half-mile west below the Church Ditch, near today’s West 102nd Avenue and Oak Street. The lake provided irrigation water for area crop fields and originally drained toward the southeast into Big Dry Creek.
Following reconstruction of the dam in 1961, the drainageway was rerouted toward the northeast to a small pond above Walnut Creek near today’s West 104th Avenue and Dover Street. Today the drainageway extends no farther east than Garland Street.
During the 1910s, this lake came to be associated with the Ketner family, for whom it has been named ever since. William Harold Ketner was born in 1881 in Iowa. By 1900 he had moved west and was living in Idaho Springs, Colo., where he worked as a dairyman supplying the mining community with food products.
Ketner’s mother and adult siblings resided in Denver, and William joined them there by 1903. The family shared a home, first in the northwest suburb of Wheat Ridge near Sloan’s Lake and then in north Denver’s Highland neighborhood. For a short time, William and his brother Oliver partnered in a grocery store known as Ketner Brothers. However, by 1904 he was working for the John Thompson Grocery Company. William continued to reside in the family home in Denver through at least 1910.
Sometime around 1915 William moved north to the countryside between Westminster and Broomfield, where he purchased a farm along the country road that passed just south of Little Church Reservoir. The farmstead was located directly south of the lake, along the north side of the unpaved road that was to become West 100th Avenue.
In 1920, William was 38 years old, still single and farming the land with the help of a hired hand. Four years later, in March 1924, he married Allie Stone, a native of Missouri who was 14 years younger. The couple continued to farm in the vicinity of Ketner Lake into at least the 1930s. They do not appear to have had children, and nothing is known about their lives beyond that time.
This lake was also associated with the Mandalay Ditch, which provided water to Ketner Lake for decades. The ditch was a project of John (Frank) and Katherine Church, members of one of the most notable pioneer ranching and farming families in the history of Westminster and northeastern Jefferson County. Katherine took over management of the family ranch and related enterprises in 1925 when her husband left to develop mining interests in southwestern Colorado. She became president of the Mandalay Irrigation Company and in this capacity worked to develop the Mandalay Ditch. In 1929, Katherine also developed plans for a country subdivision near Lower Church Lake known as Mandalay Gardens.
The Mandalay Ditch originated from a headgate at the Church Ditch (developed years earlier by John’s father, George Church), about one mile southwest of Ketner Lake. From there it ran toward the southeast and then curved toward the northeast just above and parallel to the north shore of Loon Lake, which is located across West 100th Avenue just south of Ketner Lake. It then crossed West 100th Avenue and ran north into the south side of Ketner Lake, providing it for decades afterward with fresh water from Clear Creek.
Today the lake is fed solely by stormwater runoff.