From:
Terraqua,
Inc. 2004. Battle
Creek Watershed Assessment :Characterization of stream conditions and an investigation
of sediment source factors in 2001 and 2002. Performed under contract to the
Battle Creek Watershed Conservancy, Manton, CA. Funds from the Anadromous
Fisheries Restoration Program and U.S. Fish and Wildlife Service under Agreement
DCN: 11330-1-J113.
Battle Creek WA
Methods of Identification of Pools and Measurements of Residual Pool Depth
Pool Definitions:
Pools were identified in the field if they were 1) longer than the average wetted
width, 2) channel spanning, and 3) at least 25 percent of the surface area was
scoured. In addition to pools meeting these criteria, low gradient habitat units
in high gradient stream reaches were classified as “pools” if they provided
biologically significant fish habitat compared with other habitat within the
reach. Scour pools (where fine sediments were sampled) were defined as pools
where depth was controlled by depositional materials but not by wood, bedrock
or boulders.
Residual Pool Depth:
Evaluation criteria for residual pool depth were not incorporated into the AREMP
EMDS model. The reference criteria against which residual pool depths were compared
was 3 feet for pools in anadromous reaches and 1 foot for pools not accessible
to anadromous salmonids; pools less than 3 feet deep (anadromous) or 1 foot
deep (trout) were interpreted to be fully unfavorable for anadromous salmonid
or trout production, respectively. Anadromous pool quality was assessed according
to pool depth parameters for adult spring Chinook salmon, which require pools
with depth between 3 feet to 10 feet for over-summer holding (G. Sato unpublished
data and Marcotte 1984 as cited in CDFG 1998). Non-anadromous pool quality was
evaluated according to pool depth parameters described by Behnke (1992) who
found that a lack of adult trout habitat generally limits the population biomass
of resident trout in most streams and that adult trout need slow water with
depths of 0.3 meters or greater.
