HYDRO20750

• Permit No: C1980007
• IBM Index Class Name: Hydrology
• Doc Date: 7/5/2005
• Doc Name: Evaluating the Effectiveness of Postfire Rehabilitation Treatments
• From: MCC
• To: DMG
• Permit Index Doc Type: Correspondence
• Media Type: D
• Archive: No

because of their greater depth, better layout on the
contour, and improved infiltration from deep ripping.
Straw bale check dams were judged to be effective in
11 of 16 qualitative reports (69 percent), based on
accumulation of sediment behind the structures and
structural integrity after first year storms. Failures
resulted from poor implementation or placement, or
from exceptionally large storms that exceeded dam
design.
Rtes-Kaufman (1993) reported on the failure of
straw bale, log, and sandbag check dame after the
Cleveland Fire on the Eldorado National Forest, Cali-
fornia. Thirty percent of straw bale check dams failed
from undercutting and blow outs compared to only 3
percent of log and sand bag check dame. Failures
occurred in narrow, steep drainages where only two
bales comprised the check dam. Downstream support
from rocks or logs reduced the failure rate. No esti-
mates ofthe sediment trapping efficiency were made.
Niehoff(1995) noted that atrawbale check dame had
mixed success after the Mary-Mix Fire, Clearwater
National Forest, Idaho in 1986. Straw bales placed in
]ow-to-moderately incised first and second order
channels were in place and functioning to stabilize
stream grade 1 and 9 years poatfue, Straw bale check
dame placed in deeply incised drainages were com-
pletely blown out at the end of the first year.
Kidd and Rittenhouse (1997)reportedthat 800 straw
hale check dame installed in channels after the Eighth
Street Fire on the Boiee National Forest, Idaho had a
99 percent structural integrity rate. Although these
structures were still being monitored, no estimates of
sediment trapping efficiency were available. On a
scale of"1" to "10°, straw bale check dame were rated
"9" in terms of their effectiveness. Observations of log
and rock check dame installed after the Cleveland
Fire on the Eldorado National Forest, California indi-
cated that they were effective in trapping sediment
and held up well over time (Persona 1994). No esti-
mates of sediment storage were made. Other channel
treatments of various kinds were also regarded as
effective most of the time (13 of 17, or 76 percent of
evaluations). These included channel clearing, log sill
dams, and similar measures.
Road treatments (outsloping, trashracks at culverts,
armored crossings, etc.) were specifically evaluated
only in a few narrative reports. Herman (1971) noted
that immediately after the Entiat Fire, Wenatchee
National Forest, Washington trash racks were in
place and still functioning, but had collected only
small amounts of debris due to poatfire removal of
woody material from channels. He believed that long-
termmaintenance of trash racks was necessary since
fire-killed trees would at some point begin contribut-
inglarge amounts of woody debris into channels.
Boyd and others (1995) reported on the hydrologic
functioning of made and their structures within the
Cleveland Fire, Cleveland National Forest, California
after a winter storm of 4+ in (100 mm) in 48 hours. An
oversized culvert put in place after the fire success-
fully processed large chunks of wood and rocks. A
nearby normal-sized culvert was repeated plugged
during the storm, resulting in numerous overflows
onto the road. Flanagan and Furniea (1997) described
the reduction in flow capacity by partial blockage.
During the same storm in which they examined cul-
vertfunctioning,Boydandothers(1985)obaervedthat
some correctly constructed poatfire water bars did not
have sufficient rocks or slash to dissipate the energy of
higher surface runoff. The resulting concentration
and channelization ofrunoffproduced additional small
gullies and one large, entrenched gully.
Road treatments were generally judged to be effec-
tive. Trip reports sometimes mentioned road treat-
ment effectiveness incidental to evaluating other types
of treatments.
Treatment Effectiveness Ratings
Interviewees rated the effectiveness of treatments
used on specific fires with which they were familiar
(table 16). In-channel felling, slash spreading,
atreambank armoring, trail work, rock gabion dams,
culvert inletJoutlet armoring, culvert overflow bypasses,
debris basins, culvert risers, outsloping roads, water
bars, storm patrol, and armored fords received two or
fewer evaluations per treatment and are not tabulated.
Treatments were rated across the spectrum from "ex-
cellent" to "poor,° but just over 76 percent of the effec-
tiveness ratings were either "good" or "excellent
Hillslope Treatments-Hillslope treatments are
implemented to keep soil in place and comprise the
greateet effort in moat BAER projects. Aerial seeding,
the moat frequently used BAER treatment, was rated
about equally across the spectrum from "excellent" to
"poor." The rating for contour-felled logs was "excel-
lent" or "goodA in 66 percent ofthe evaluations. Mulch-
ing was rated "excellent" about the same amount
(67 percent), and nobody considered it a "poor" treat-
ment. Nearly 82 percent of the evaluations placed
ground seeding effectiveness in the "good" category.
There was a 100 percent concurrence that silt fences
were "excellent" or "good" as a BAERtreatment. Evalu-
ations of seeding plus fertilizer covered the spectrum
from "excellent" to "poor,' although most responses
were "fair" or "poor.° The remainder of the hillslope
treatments, received only three evaluations each, so it
is difficult to come up with conclusions beyond the fact
that they were generally rated "excellent,° "good,° or
"fair" and none were evaluated as being "poor.'°
36 USDA Forest Service Gen. Tech. Rep. RMRS-GTRb3. 2000