South West South West WaterwaysWaterways

Values, Condition & Values, Condition & ImpactsImpacts

A context for water issues in the A context for water issues in the West RFAWest RFA

South West South West WaterwaysWaterways

Values, Condition & Values, Condition & ImpactsImpacts

A context for water issues in the A context for water issues in the West RFAWest RFA

Dr. Tim Dr. Tim FletcherFletcherDr. Tim Dr. Tim FletcherFletcher

IntroductionIntroduction General presentation - General presentation - sets the context for sets the context for

more specific presentations which followmore specific presentations which follow

The information presented is not “new” The information presented is not “new” — it is a broad summary of the state of it is a broad summary of the state of

knowledge of regional waterwaysknowledge of regional waterways

Presents the big picture of waterways in Presents the big picture of waterways in the region - both the condition & impactsthe region - both the condition & impacts— puts RFA water issues in regional contextputs RFA water issues in regional context

OutlineOutline Waterways in the West RFA regionWaterways in the West RFA region

Values & uses (demands) of Values & uses (demands) of waterwayswaterways

Impacts on waterwaysImpacts on waterways

Condition of regional waterwaysCondition of regional waterways

Methods to protect waterway Methods to protect waterway valuesvalues

Waterways within the Waterways within the West RFAWest RFA

Covers part of 16 river basinsCovers part of 16 river basinsGoulburnGoulburn CampaspeCampaspeLoddonLoddon AvocaAvocaYarraYarra MaribyrnongMaribyrnongWerribeeWerribee Wimmera-AvonWimmera-AvonMooraboolMoorabool BarwonBarwonOtway CoastOtway Coast Lake CorangamiteLake CorangamiteHopkinsHopkins Portland CoastPortland CoastGlenelg Glenelg MillicentMillicent

Waterways in the Waterways in the Corangamite regionCorangamite region

(Barwon, Moorabool, Lake Corangamite & Otway (Barwon, Moorabool, Lake Corangamite & Otway Coast Basins)Coast Basins)

Colac

Geelong

Apollo Bay

Ballarat

Lismore

Forrest

Meredith

Timboon

Port Campbell

Cobden

Simpson

Winchelsea

Anglesea

Anakie

Linton

CamperdownM

oorabool RLake

Corangamite

Barwon RL

eigh RWoady

Yaloak R

Curdies R

Gellibrand R

Aire R

Waterway Values & Waterway Values & UsesUses

EnvironmentalEnvironmental

EconomicEconomic

SocialSocial

Many competing Many competing demands...demands...

Economic & Social Economic & Social ValuesValues

Water supplyWater supply— drinking & domestic (e.g. garden watering), industrial, drinking & domestic (e.g. garden watering), industrial,

agriculture (stock & irrigation)agriculture (stock & irrigation)

ExtractionExtraction— fish, gravel, sand, soil (floodplain)fish, gravel, sand, soil (floodplain)

Tourism & recreationTourism & recreation— walking, sightseeing, fishing, boating, swimmingwalking, sightseeing, fishing, boating, swimming

AestheticsAesthetics— rural landscape, parkland, urban designrural landscape, parkland, urban design

Waste dischargeWaste discharge— sewerage, industry, stormwatersewerage, industry, stormwater

Environmental ValuesEnvironmental Values InstreamInstream

— habitat for fish, macroinvertebrates habitat for fish, macroinvertebrates (“bugs”), macrophytes (“plants”)(“bugs”), macrophytes (“plants”)

Riparian (streamside) zoneRiparian (streamside) zone— habitat corridor, unique landscape element habitat corridor, unique landscape element

(ecotone)(ecotone)

FloodplainFloodplain— intermittent habitat (billabongs), nutrient intermittent habitat (billabongs), nutrient

transfer, sediment depositiontransfer, sediment deposition

Dynamic, variability, diversityDynamic, variability, diversity

Impacts on Impacts on WaterwaysWaterways UrbanisationUrbanisation

AgricultureAgriculture

ForestryForestry Others (e.g. mining)Others (e.g. mining)

Impacts of Urbanisation Impacts of Urbanisation (e.g (e.g

Geelong, Ballarat)Geelong, Ballarat)

HydrologyHydrology— increased impervious area, decreased vegetation cover increased impervious area, decreased vegetation cover

““flashy catchments” - rapid flows over short timeflashy catchments” - rapid flows over short time leads to downstream erosion & scouringleads to downstream erosion & scouring

— river isolated from its floodplainriver isolated from its floodplain— extraction of flows for water supplyextraction of flows for water supply

Water qualityWater quality— increased sediment transportincreased sediment transport— increased nutrients (N, P) - sewerage, fertilisers, etcincreased nutrients (N, P) - sewerage, fertilisers, etc— reduced dissolved oxygen (DO)reduced dissolved oxygen (DO)— pathogens, heavy metals, hydrocarbons, litterpathogens, heavy metals, hydrocarbons, litter

Channel & riparian zoneChannel & riparian zone— gross modificationgross modification— channelisation, clearing of vegetation - channelisation, clearing of vegetation - loss of diversityloss of diversity— barriers to fish passage (weirs, culverts, etc)barriers to fish passage (weirs, culverts, etc)

Impacts of AgricultureImpacts of Agriculture HydrologyHydrology

— Vegetation removal Vegetation removal ((runoff, erosion, runoff, erosion, groundwater, salinity) groundwater, salinity)— Diversion & storage of stream waterDiversion & storage of stream water

impacts on aquatic communities (flora & fauna)impacts on aquatic communities (flora & fauna)— Flood control (levees, etc)Flood control (levees, etc)

river isolated from floodplain, flow concentration, erosionriver isolated from floodplain, flow concentration, erosion

Water QualityWater Quality— sediment & nutrients (fertiliser use, stock access & sediment & nutrients (fertiliser use, stock access &

cropping, soil erosion)cropping, soil erosion)— pathogens (stock access)pathogens (stock access)— potential chemical contamination (herbicide/pesticide)potential chemical contamination (herbicide/pesticide)— changed organic inputs, dissolved oxygen levelschanged organic inputs, dissolved oxygen levels

Impacts of Agriculture Impacts of Agriculture (cont.)(cont.)

Channel & Riparian ZoneChannel & Riparian Zone— vegetation removal (changed shade, temperature, vegetation removal (changed shade, temperature,

etc)etc)

— de-snagging, channel “cleaning” & “straightening”de-snagging, channel “cleaning” & “straightening” loss of habitatloss of habitat

— channel deepening & erosion (from increased runoff)channel deepening & erosion (from increased runoff)

— fish barriers (storages, weirs, poorly designed fish barriers (storages, weirs, poorly designed crossings)crossings)

— reduced physical and biological diversityreduced physical and biological diversity smaller range of habitats (suits less species)smaller range of habitats (suits less species)

Impacts of ForestryImpacts of Forestry HydrologyHydrology

— short and long-term changes to water yieldshort and long-term changes to water yield— presentation by Dr. Rob Vertessypresentation by Dr. Rob Vertessy

Water qualityWater quality— sediment mobilisation & transportsediment mobilisation & transport— presentation by Dr. Jacky Crokepresentation by Dr. Jacky Croke

Channel & riparian zoneChannel & riparian zone— short or long-term changes to vegetation short or long-term changes to vegetation

structurestructure depending on proximity of harvestingdepending on proximity of harvesting

— generally less than urbanisation or agriculturegenerally less than urbanisation or agriculture

Condition of Waterways Condition of Waterways in SW Vicin SW Vic

Two comprehensive assessments Two comprehensive assessments of environmental condition:of environmental condition:

— Mitchell (1990)Mitchell (1990) 96 sites96 sites

— Index of Stream Condition (ISC) Index of Stream Condition (ISC) (1999)(1999) 217 sites217 sites

Condition Assessment - Condition Assessment - ISCISC

HydrologyHydrology— deviation from natural flowsdeviation from natural flows

Physical formPhysical form— bed & bank stabilitybed & bank stability— barriers to fish passagebarriers to fish passage— instream habitat (snags, etc)instream habitat (snags, etc)

Streamside zoneStreamside zone— vegetation cover & condition, weeds, regenerationvegetation cover & condition, weeds, regeneration

Water qualityWater quality— total phosphorus, turbidity, EC, pHtotal phosphorus, turbidity, EC, pH

Aquatic lifeAquatic life— macroinvertebrate population diversitymacroinvertebrate population diversity

Five sub-indicesFive sub-indices Index of Stream Condition Index of Stream Condition

ResultResultss

Excellent Excellent 13%13%

Good Good 25%25%

Moderate Moderate 26%26%

Poor Poor 29%29%

Very Poor Very Poor 7%7%

ExcellentExcellent— Generally in forested Generally in forested

areas:areas: Otways (e.g. Otways (e.g.

Gellibrand, Barham, Gellibrand, Barham, Ford Rivers)Ford Rivers)

Moorabool River (e.g. Moorabool River (e.g. below Lal Lal below Lal Lal Reservoir)Reservoir)

Very PoorVery Poor— Generally in/near urban areas, or Generally in/near urban areas, or

where intensive agriculture is present:where intensive agriculture is present: Naringhil & Kuruc-a-Ruc CksNaringhil & Kuruc-a-Ruc Cks Yarrowee River & Winter Ck (near BallaratYarrowee River & Winter Ck (near Ballarat))

Mitchell, Mitchell, 19901990

ResultsResults(Mitchell (Mitchell

1990)1990)

Moorabool Excellent (%) 0%

Good (%) 11%Moderate (%) 47%

Poor (%) 39%Very Poor (%) 3%

Barwon Excellent (%) 0%

Good (%) 48%Moderate (%) 12%

Poor (%) 28%Very Poor (%) 11%

Corangamite Excellent (%) 0%

Good (%) 0%Moderate (%) 46%

Poor (%) 41%Very Poor (%) 13%

Otway Excellent (%) 35%

Good (%) 18%Moderate (%) 24%

Poor (%) 23%Very Poor (%) 0%

Good (%) 25%Moderate (%) 26%

Poor (%) 30%Very Poor (%)

Mundy Mundy Gully, Gully, LismoreLismore

Winter Winter CreekCreek

YarroweYarroweee

RiverRiver

MoorabMoorabool ool RiverRiver

Ford Ford RiverRiver

GellibraGellibrandRiverndRiver

Moorabool RiverMoorabool River

Aire RiverAire River

How can we best protect How can we best protect our waterways?our waterways?

Considering thatConsidering that

— there are many different there are many different values/uses of land and watervalues/uses of land and water

……..

Protecting waterway Protecting waterway values...values...

Initial assessment of capability/impacts Initial assessment of capability/impacts of the particular useof the particular use

Best practice land useBest practice land use— urbanisationurbanisation— agricultureagriculture— forestryforestry

BUTBUT all of the above depend on all of the above depend on Long-term environmental monitoringLong-term environmental monitoring

— both broad scale/background both broad scale/background && specific specific

Some referencesSome referencesMitchellMitchell (1990). (1990). The environmental condition of Victorian The environmental condition of Victorian

streamsstreams

Ladson & WhiteLadson & White (1999). (1999). An index of stream condition: An index of stream condition: reference manualreference manual

Commissioner for the EnvironmentCommissioner for the Environment (1988). (1988). State of the State of the environment report 1988 - Victoria’s inland watersenvironment report 1988 - Victoria’s inland waters

Corangamite CaLPCorangamite CaLP (1997). (1997). Corangamite Regional Corangamite Regional Catchment StrategyCatchment Strategy

Fletcher & BrenFletcher & Bren (1999). (1999). Cumulative effects analysis; Cumulative effects analysis; grasping the big picture of environmental change grasping the big picture of environmental change in rivers. in rivers. In Proceedings of 2nd Australian Stream Management In Proceedings of 2nd Australian Stream Management ConferenceConference