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• Board Meeting Date: 3/18/2008
• Description: ISF Section - Injury with Mitigation - Case No. 3-99CW34 - Application of Charles Nearburg
• Board Meetings - Doc Type: Memo

The Channels provide additional aquatic habitat, including deep water fish refuge. Surface diversions from Trout
Creek into the Channels will be limited to the period from May 1 to October 15, with no surface diversions
occurring during the period from October 16 to April 30. Mr. Nearburg's application claims a diversion rate of 1
c.f.s. for each of the Channels. However, these diversions will be made in series, water diverted by each Channel
will return to Trout Creek above the inlet to the next downstream Channel, so the total maximum impact to the
Trout Creek instream flow reach will never exceed 1 cfs.
To further minimize any potential impact to the natural environment of Trout Creek, the Channels will divert at a
rate of less than 1 c.f.s. when flows in Trout Creek drop below specific amounts, and all diversions into the
Channels will cease when the gaged flow in Trout Creek is less than or equal to 15 c.f.s. Specifically, surface
diversions into the Channels will be limited as follows:
When the total native flow in
Trout Creek at the gage is
greater than or equal to (cfs): Then surface diversions into the
Channels (in series) shall not
exceed (cfs):
26 1
25.9 0.9
25.8 0.8
25.7 0.7
25.6 0.6
15.5 - 25.5 0.5
15.4 0.4
15.3 0.3
15.2 0.2
15.1 0.1
No diversions will be made when flows at the gage are less than or equal to 15 cfs.
Mitigation Proposal -Improvements to Trout Creek
Charles Nearburg has made significant efforts to restore and improve Trout Creek through the Trout Creek Ranch
property. Specifically, major restoration projects were successfully completed in both 1998 and 2001 on Trout
Creek. These projects restored over 8500 linear feet of the Trout Creek stream channel, and involved bank
stabilization, shaping of over-widened and braided channels, removal of excess gravel deposits, installation of 45
rock boulder cross vane structures for grade control and to create pools, and installation of 60 rock vanes and
additional woody natural structures for bank protection. Prior to these restoration efforts, Trout Creek through the
Trout Creek Ranch was typically a wide, shallow riffle stream with little or no holding capacity for fish. These
restoration efforts have substantially improved the hydraulic conditions of the stream and increased the ability of
Trout Creek to sustain aquatic biota and the natural environment with lower flows.l
In 1999 and 2000, Wright Water Engineers conducted a bioassessment of Trout Creek, including a hydraulic
analysis to evaluate the three principal criteria (average depth, average velocity, and percent wetted perimeter)
used by the CDOW and CWCB to develop biologic instream flow recommendations. This analysis measured
and modeled flows in Trout Creek at three different stations, and used methods similar to the CWCB's R2CROSS
Methodology. The upper-most location (Station 1) was chosen because it is located in an un-restored riffle
section of Trout Creek, while the lower stations are located in restored riffle and meander sections of Trout Creek
on Mr. Nearburg's property.
Wright Water concluded that, at Station 1 (an un-restored stream riffle location), only one of the CWCB hydraulic
criteria was satisfied at flow rate of 35 c.f.s. (the decreed summertime instream flow rate). However, at Station 2
(a restored stream riffle location) all three hydraulic criteria were satisfied at a flow rate of 25 c.f.s., and two out
of three criteria were satisfied at a flow rate of 15 c.f.s. At Station 3 (a restored stream meander location) the flow
was concentrated to one side of the stream channel and the channel width was somewhat wider than at Station 2,
1 The restoration efforts are described in significant detail in a May 2007 report from Black Creek Hydrology and February
2000 reports from Wright Water Engineers.