To Get There
Castlewood
Canyon
State Park
The Castlewood Dam
The Bridge That Was
There was no modern machinery in 1889, so the
Castlewood Dam was built by man, mule, and
horse power alone – and was considered quite an
engineering achievement. The dam had two walls
set several feet apart. The wall facing the reservoir
was masonry laid up with cement. The downstream
wall, acting as a brace, was angled at 45 degrees,
creating a pleasing “step” appearance. The space
between the walls was filled with large stones
laid in place by hand. Broken rock and dirt were
hammered into spaces between the big stones. At its
base, the dam was 83 feet thick. Eight valves in the
center of the wall could be opened to release water
for irrigation, or to relieve pressure on the dam
when the reservoir was full.
The dam is located about halfway between the
Canyon Point parking lot and the Falls parking
lot of Castlewood Canyon State Park. It is
approximately one mile from either lot. You can
see the dam if you drive along Castlewood Canyon
Road (Douglas County Highway 51). There is no
parking on the road at the dam.
Castlewood Canyon State Park
2989 S. State Highway 83
Franktown, CO 80116
303-688-5242
Email: castlewood.canyon@state.co.us
www.parks.state.co.us
CSP-CAST-200-4/07
It Leaked from the Beginning
Image Courtesy of Colorado Historical Society
Luring Settlers With Water
Imagine yourself a land owner in the late 1880s.
Your land lies on the high plains east of the Rocky
Mountains and south of the city of Denver. What
would you do to attract buyers for your land?
You know that the most likely buyers are farmers
and ranchers because Denver needs nearby sources
of food supplies for its growing population. But
there was something very important missing from
your land – enough water to grow the crops and
water the livestock of all the new settlers. You
can’t make more water flow in Cherry Creek and
the many springs that feed it, but you could store
the water... in a big reservoir, behind a big dam.
So you get together with other land owners, form
the Denver Water Storage Company, and build
the Castlewood Dam. Even with 1880s knowledge
and technology, it only took 11 months to build
the 600-foot-long dam, which was 70 feet high and
eight feet wide at the top. An estimated 85 men and
many teams of horses and mules wrestled the rocks
into place according to the design of Chief Engineer
AM. Welles. Total cost: $350,000.
The dam, completed in October of 1890, began to
leak almost immediately. Denver citizens worried
the dam would break, sending flood waters rushing
downstream to their city. Ominously, heavy rains
in 1897 washed out about 100 feet of the dam,
but it was repaired. After severe rainfall in spring
1900, Chief Engineer Welles responded to rumors
that the dam was about to break by writing a
letter to the Denver Times newspaper, which read:
“The Castlewood Dam will never, in the life of any
person now living or in generations to come,
break to an extent that will do any great damage
either to itself or others from the volume of
water impounded, and never in all time to the
city of Denver.”
Ownership of the dam changed eight times between
1890 and 1933. Each new owner tried different
financial schemes to attract buyers to downstream
properties and different ways to shore up confidence
in the dam, but every one failed.
The dam continued to leak. From the photo below,
it’s clear there was a large leak on the west side
of the dam. But look closely at the very bottom
of the dam. See that small stream of water? Look
at the dam ruins in the park today. The west side
of the dam still stands. It was the middle that
collapsed. Could that small leak have weakened the
George Engle had homesteaded a ranch south of
the dam site in 1860. His wife Louisa cooked and
delivered two meals a day to the men building the
dam. Some stories say the reservoir behind the dam
was named Lake Louisa in her honor.
footings of the dam enough to fail? Walk below the
dam ruins and look for the type of rock it was built
on. Would you have built a dam on that rock?
The Night the Dam Failed
It rained hard the first two days of August in 1933.
The reservoir was full and water poured over the
top of the dam. Dam caretaker, Hugh Paine, was
uneasy the night of August 2. Lightning crackled,
thunder rumbled, and rain fell in buckets. At
1:20 a.m. on August 3, Paine heard the first
rumbling of the flood loosened by the broken dam.
An estimated 1.7 BILLION gallons of water was
released in a raging torrent that scoured the canyon
walls and headed for Denver. Hugh Paine made
it to Castle Rock and called the Parker phone
exchange. Telephone operator Nettie Driskill’s
efforts to alert people downstream no doubt saved
many lives that night.
The wall of water grew higher as it approached
Denver and reached the city about 7:00 a.m. It
traveled down the concrete canal that follows
Speer Boulevard. Reports vary about the depth of
the water, but aerial photos show that much of the
lowlands along Cherry Creek and the South Platte
River were submerged. Damage was extensive, but
only two people died.
Looking down Speer Boulevard
Images Courtesy of Colorado Historical Society
