WSP01843

• File Number: 5000.100
• Description: Flood Protection Section - Coal Creek Project
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 7/21/1980
• Author: City of Louisville
• Title: City of Louisville - Coal Creek Proposal
• Water Supply Pro - Doc Type: Report/Study

001738

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breeding condition. Further downstream, close to the
discharge but still above it, the fish population is much
smaller. Just below the discharge, only two fish were found,
and near the confluence of Coal Creek with Boulder Creek, only
one fish was found.

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From all 0 f the above, I conol ude the fa Hawing: ([)
without any sewage discharges, water diversions, or other
disturbances, Coal Creek, like Boulder Creek, would be able to
support a relatively large population of warmwater fish. There
is no evidence that these populations of warmwater.fish would
include any substantial number of game fish, however, (2) there
is a substantial degradation of Coal Creek with respect to the
fish fauna by the time the creek reaches the vicinity of
Louisville but before the Louisville discharge enters it, (3)
there is a further substantial degradation of Coal Creek from
the viewpoint of warmwater fish fauna below the Louisville
discharge and persisting to the confluence of Coal Creek and
Boulder Creek.

Conclusions Concerning Other Features of Coal Creek
Important to Its Classification. Although good streamflow
records are not available, it would appear from anecdotal
information (e.g. see State of Colorado Stream Classification
Survey Forms) that, at times of lowest flow, Coal Creek barely
flows at all except for waste treatment discharges. The low
flow conditions may be sufficiently extreme to affect the
composition and abundance of warmwater fishes. The future
potential of Coal Creek as a sport fishery cannot be considered
without attention to the limitations imposed by low
streamflow.

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Another aspect of the stream that may be relevant to its
classification is the condition of the streambed. In June of
1980, much 0 f the st reambed was in very poor cond it ion. In the
uppermost reaches of the stream, the streambed was rocky. A
kilometer or more above Louisville, however, the streambed was
taken over by sand. This became progressively more pronounced
below Louisville toward the confluence with Boulder Creek.
Over this entire stretch, the streambed consisted almost
entirely of sand. According to local residents, this has not
always been the case. The sand bottom is not as productive and
not as ideal for the establishment of a good warmwater fish
fauna. The stretch from Louisville down has much the character
of an irrigation ditch rather than a quality stream at the
present time.

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A third factor to be considered is turbidity.
observations in June of 1980 showed that, beginning
above Louisville and extending to the lower reaches

The
at a point
of the

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