Wambo Coal AEMR 2011-2012 - Peabody Energy

2011-2012 AEMR
Riparian EFA
Riparian assessments which included taking
pedestrian based surveys along sections of North
Wambo Creek, South Wambo Creek and Stoney
Creek utilising field sheets to give an overall rating
of creek health were undertaken over four days in
November 2011. Two types of transect were
assessed for each of the three streams, these were:
Cross sectional – A marked single line transect
across the width of the stream from bank to
bank, hereafter referred to as ‘transects’; and
Longitudinal – An unmarked transect along the
length of the creek between two transects,
hereafter referred to as ‘sections’.
There are two types of riparian monitoring including
bed and bank stability monitoring, and riparian
vegetation monitoring.
Bed and bank stability monitoring is undertaken by
surveying consultants who undertake replicate
surveys of the three creeks to measure areas of
significant erosion and to identify changes related to
water flow. A written assessment was completed of
any areas of significant erosion, bare soil and visible
subsidence along each creek line. The results were
not finalised at the times of preparing the AEMR.
The results of the bed and bank stability for 2011-
212 will be included in the next AEMR.
Riparian Monitoring Condition Scores
Riparian Vegetation Monitoring
The effects of subsidence and erosion on riparian
vegetation were monitored by repetitive sampling of
established permanent transects. Riparian
monitoring identified Stoney Creek as being in good
condition, and North Wambo and South Wambo
Creeks in moderate condition. Current bank erosion
problem areas are a result of historic land
management practises however in the absence of
current management will continue to degrade.
Subsidence has also been recorded during 2011
annual assessments. Impacts from mining
subsidence were found along North Wambo creek.
Rock formations at the base of the creek bed
experienced both compression and expansion as a
result of subsidence. Natural fault lines within the
rock as well as solid rock segments experienced
expansion within a range of 6–20 mm.
The subsidence impacts are consistent with the
predictions made in the SMP. Invention measures to
address affected areas will be reported in the next
AEMR.
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