Wambo Coal AEMR 2010-2011 - Peabody Energy

2010-2011 AEMRdesigned the diversion (Gilbert and Associates) anda Hunter Valley based consultancy that specialisesin rehabilitation and erosion control (GSSEnvironmental). The two inspection reports (GSSE,October 2009, and Gilbert & Associates, September2009) identified several areas requiring remedialattention.During the reporting period, WCPL preparedtenders for the remedial rehabilitation works withinStage 2 NWC Diversion, based on therecommendations provided from both GSSE andGilbert’s. After completing the Tendering processand awarding contracts, rehabilitation works withinStage 2 of the NWC Diversion commenced in April2011, with works completed during June 2011.Planning for Stage 3, the final stage of the NWCDiversion, commenced during 2010-2011. Stage 3has a construction zone of approximately 1.8km,which includes approximately 2.83km of replicatedcreek line. The current project program is twelvemonths with a start date in August 2011 and acompletion date estimated during July 2012. Detailsof the completed NWC Diversion will be reported inthe next AEMR.5.2 Rehabilitation Trials andResearchDuring the previous reporting period, WCPLcommenced incorporating biosoilds into the OpenCut rehabilitation program. A wider application areawas planned for the current reporting period, as wellas trial application of organic compost material. Asno rehabilitation was completed during this reportingperiod, application of biosoilds and organic compostis expected to occur during the next reportingperiod. An update on the biosoild application will beprovided in the next AEMR.Supplementary planting of a native grass speciesseed mix, in areas of patchy tree establishment, isalso planned for the next reporting period.The use of mobile tree mulching plant is planned forthe next reporting period. After identification andseparate recovery of timber and habitat trees, themulcher will mulch trees in situ, leaving a blanket ofmulch, which assists with dust suppression anderosion control, as well as providing a source oforganic matter in the stripped topsoil.5.3 Rehabilitation MonitoringDuring the reporting period a program of worksassociated with the monitoring of revegetateddisturbed riparian lands utilising the CSIROdeveloped Ecosystem Function Analysis (EFA)monitoring tool was undertaken. A separate surveyand report has been prepared for the monitoring ofrehabilitated areas associated with the Open Cutareas.The data that has been derived from the monitoringprogram provides a scientifically robust platformagainst which the effectiveness of rehabilitationtechniques can be assessed and where applicableamended, with a view to achieving sustainablevegetation communities on disturbed landscapes.The purpose of the assessment is to determinewhether rehabilitated areas are on a trajectorytoward self sustainability and functionality.The riparian areas surveyed included South WamboCreek and North Wambo Creek downstream of theOpen Cut offices. The second component of theriparian monitoring program commenced in 2008and focused on the North Wambo Creek Diversionrehabilitation works.5.3.1.1 Ecosystem Function AnalysisSummaryOpen Cut EFARPS was engaged by WCPL to undertake the 2010EFA monitoring of 14 previously established opencut EFA transects. Twelve EFA transects wereestablished in 2006 comprising:Six pasture rehabilitation transects;Four woodland rehabilitation transects;One pasture analogue transect; andOne woodland analogue transect.A further two pasture rehabilitation transects werecreated in 2008. During 2009 two pasturerehabilitation transects were repositioned to morerepresentative pasture rehabilitation locations.During 2010 six new transects were established,comprising:Two pasture analogue transects;Two woodland analogue transects; andTwo pasture rehabilitation transects.The total of 20 EFA transects were investigatedduring 2010 and comprised:Three analogue woodland transects;Four rehabilitation woodland transects;Three analogue pasture transects; andTen rehabilitation pasture transects.With the exception of two transects all other pasturerehabilitation transects recorded LFA score similarto the analogue transects in 2010 suggesting that,at least during 2010, many of the rehabilitationPage 86