|
<br />It too is formed by a concrete-lined earthen dam which is approxi-
<br />mately 0.5 mile long. Work on this reservoir was initiated in
<br />1906.
<br />
<br />Lord Reservoir is fed by Lost Creek and its tributaries. The
<br />total tributary drainage area is 59 square miles. It is also
<br />supplied water by a feeder ditch from the Denver Hudson Canal out
<br />of Horse Creek Reservoir. The maximum unrestricted operating
<br />capacity of Lord Reservoir is 1,450 acre-feet with a water surface
<br />area of 270 acres and a gage height of 11.0 feet to the concrete
<br />service spillway. In 1976, the State Engineer imposed a hold
<br />order on Lord Reservoir which restricted the maximum water level
<br />at 2.0 feet below the emergency spillway. At this level, the water
<br />surface area is about 230 acres and the storage capacity is
<br />approximately 960 acre-feet. The outlet works feed the Lowline
<br />Canal for irrigation in the Lower Prospect Valley.
<br />
<br />The State Engineer has classified Lord Reservoir as a
<br />moderate hazard dam. On June 14, 1949, the Lord Reservoir Dam
<br />failed due to heavy rains in the Lost Creek Basin. The
<br />resulting flood caused considerale damage to farms and to the town
<br />of Roggen, Colorado. Newspaper accounts of this event are pre-
<br />sented in Appendix C.
<br />
<br />THE FLOOD
<br />
<br />In the early morning of Sunday, February 10, 1980, Prospect
<br />Valley Reservoir contained 5,850 acre-feet of water, 93 percent of
<br />its capacity. The depth of water was 36 feet.
<br />
<br />About 9:00 a.m., the Prospect Reservoir Dam began to fail at
<br />a point approximately 800 feet from the southern end of the
<br />embankment. The cause of the break is attributed to piping. A
<br />10-foot diameter tunnel in the embankment was observed by a local
<br />farmer ~t about 9:30 a.m. Erosion of the embankment progressed
<br />rapidly. By 9:55 a.m., the breach was estimated by an observer to
<br />be approximately 30 feet wide. As erosion continued, the gap
<br />spread at an average rate of 2.3 feet per hour to a final breach
<br />
<br />FIG. 4
<br />
<br />
<br />. \. '~:~!J2 r '--5\ J: ' ~; '--"r";J: ,'-:.~,..c
<br />f ~ -- .' ~ i :'; \, t::q
<br />i", Jiv'>,'; \ <''t ,,','1\1.'
<br />;" ",.; \,,,,! \:.3)'1;'~'~.!" V
<br />'''..,.., I " .J 'l: ,u ~ I'"
<br />- ,m;r 4t~~~\;f.-[/t~-----'i..L -o~\r--->:~, -;~',
<br />
<br />,'_ {':~i~~~{:('
<br />I ~ ,I :1
<br />( I
<br />.~-I-
<br />f '\ I
<br />J'm....rr...LL,
<br />. ~ i
<br />~... r
<br />i. \:." . r~...... , <:.::' ~:: t .' ',f
<br />
<br />',---~. N ' L.. :: ., .
<br />~" .......m. ",:::"'1' ':'r --~---' .13
<br />n.~ ,~~._ j
<br />: /.1" ~
<br />,"" ~ I I : I
<br />l _ '....1 '~.
<br />
<br />i . i
<br />. .- 0 I 2ml.
<br />:~~Kr'UU f~' '., !
<br />-'1~;'[ t:~ "": ~:'rt ? il:--~,~,'i
<br />.' J i \~' . ".~,.- ~r~'" (, ). '\. ! i
<br />T "J" V A L L,~, .f,- j t -',
<br />-:r-~~ -ii>2t~'"1 ---i--.r~- ~.. ' - - "'\'fr 11--"""':'
<br />- ' I
<br />,.' LORD RESERVOIR if"
<br />','
<br />
<br />..P.-'~" .
<br />
<br />"
<br />
<br />1 ,>.::.,,- _..no=
<br />
<br />, \\
<br />
<br />",
<br />
<br />';'1
<br />,[
<br />'I~ I '
<br />-~1--
<br />I; I
<br />t-",
<br />
<br />~ :
<br />fr--~
<br />
<br />_..;E.
<br />
<br />,~,~" PROSPECT
<br />J o_~ !.Jr./ ~~i~)I. c
<br />
<br />-~,
<br />
<br />RESERVOIR
<br />k./ 1',"
<br />. _ ~~'2!!' '
<br />
<br />"
<br />
<br />1
<br />~il:.'~_
<br />
<br />4
<br />
<br />VICINITY
<br />
<br />MAP
<br />
|