South Creek Subcatchment
Total Page:16
File Type:pdf, Size:1020Kb
South Creek Appendix 4.2 Appendix Subcatchment summaries Subcatchment South Creek Subcatchment South Creek The South Creek subcatchment encompasses most of the Cumberland Plain of Western Sydney. The catchment is a shale-based catchment with no gorges or sandstone dominated landscapes. The majority of the streams are “meandering vertical” river channel types streams, which are under great threat as they are confi ned largely to the Cumberland Plain in the Hawkesbury Nepean catchment. South Creek subcatchment is perhaps the most degraded subcatchment in the Hawkesbury Nepean. Hydrological and sediment regimes have been dramatically altered due to catchment vegetation clearance and increasing urbanisation. Increasing impervious surfaces in the catchment are causing changes to hydrology which has greatly altered the geomorphology and ecology of the watercourses. A number of major Sewerage Treatment Plants discharge into South Creek and these, along with stormwater from urban areas and agricultural run off , contribute to the poor water quality of the streams. The recovery potential of the catchment’s streams is very low; however, there are some very important remnants of endangered vegetation along the riparian zones. The watercourses form extremely important habitat corridors although heavy woody weed invasion exists in the riparian zones. HAWKESBURY NEPEAN RIVER HEALTH STRATEGY 69 70 70 Reach Management Recommendations – South Creek Subcatchment Reach Name Reach Riparian Land Reach Values Reach Threats Reach management recommendations Description Management (Planning, Education, Works, Monitoring, Institutional) Category South R1 St Gregorys Revegetation • Signifi cant vegetation community • Modifi ed / engineered channel (local stormwater • Revegetation with indigenous riparian vegetation (W) College to end (Cumberland Shale Hills Woodland) works) • Management of aquatic weeds of cut and fi ll • Aquatic weed outbreaks • Management of stock impact on waterways (W) HAWKESBURY NEPEAN CATCHMENT MANAGEMENT AUTHORITY MANAGEMENT NEPEAN CATCHMENT HAWKESBURY HAWKESBURY NEPEAN CATCHMENT MANAGEMENT AUTHORITY MANAGEMENT NEPEAN CATCHMENT HAWKESBURY section • Damaging access (humans and stock) • Encourage adoption of sustainable land management • Flow extraction practices in riparian lands (E) • Water quality • Manage human impacts at public recreation river access points and along foreshores (E,W) Action Triggers • Removal/replacement of exotic riparian vegetation (W) • Severe downstream impact (weeds; water • Increase community capacity for environmental quality) restoration (E) • Water quantity / fl ow management (I) • Water quality / nutrient management (I) South R2 From end of cut Assisted • Good riparian vegetation cover (but • Modifi ed / engineered channel and fi ll section to Regeneration discontinuous) • High woody weed invasion (African Olive, Privet) • Removal/replacement of exotic riparian vegetation (W) confl uence with • Wetland of regional or state • Aquatic weed outbreaks (Salvinia, Water • Riparian wetland management Hawkesbury River signifi cance (McGraths Hill Hyacinth) • Management of aquatic weeds at Windsor Wetlands) • Damaging access (stock on private land and • Management of stock impact on waterways (W) • Rare or threatened river category damaging human access at public sites) • Encourage adoption of sustainable land management (Meandering Vertical) • Barriers to ecosystem functioning practices in riparian lands (E) • Signifi cant vegetation community • Flow extraction • Manage human impacts at public recreation river access (Cumberland Shale Plains • Water quality points and along foreshores (E,W) Woodland; Cumberland River Flat • Aquatic habitat condition and connectivity improvement Forest; Castlereagh Shale-Gravel Action Triggers (P,W) Transition Forest) • Rare or threatened river category (Meandering • Water quantity / fl ow management (I) • Popular recreational fi shing Vertical) • Water quality / nutrient management (I) • Identifi ed fl agship species • Severe downstream impacts (water quality and • Maintain existing community based environment activity (Eucalyptus beaureana) weeds) (E,P) • Signifi cant irrigation water supply • Severe immediate threat (contaminants in bed • Signifi cant community based sediments) environment activity Eastern R1 Headwater from Revegetation • High public recreation access • Modifi ed / engineered channel • Revegetation with indigenous riparian vegetation (W) Regional Park to (Sydney Regional Park) • High woody weed invasion • Removal/replacement of exotic riparian vegetation (W) confi ned section • Aquatic weed outbreaks (Salvinia and Water • Management of aquatic weeds Hyacinth) • Aquatic habitat condition and connectivity improvement • Barriers to ecosystem functioning (P,W) • Flow extraction • Urban water quantity and fl ow management (I,W) • Water quality • Urban water quality and sediment management (I,W) • Increase community capacity for environmental Action Triggers restoration (E) • Severe downstream impact – water quality HAWKESBURY NEPEAN RIVER HEALTH STRATEGY NEPEAN RIVER HEALTH HAWKESBURY Reach Management Recommendations – South Creek Subcatchment Reach Name Reach Riparian Land Reach Values Reach Threats Reach management recommendations Description Management (Planning, Education, Works, Monitoring, Institutional) Category Eastern R2 Concrete lined Revegetation • Fully engineered channel – concrete lined • Revegetation with indigenous riparian vegetation (W) channel • Aquatic weed outbreaks (Salvinia; Water • Management of aquatic weeds Hyacinth) • Flow extraction • Water quality • Urbanisation • Lack of community based environment activity Action Triggers • Severe downstream impacts – water quality; fl ow alteration through concrete section Eastern R3 From concrete Assisted • Good riparian vegetation cover • Modifi ed / engineered channel • Riparian wetland management lined section to Regeneration • Wetland of local signifi cance • High woody weed invasion • Removal/replacement of exotic riparian vegetation (W) confl uence with • Rare or threatened river category • Aquatic weed outbreaks (Salvinia, Water • Management of aquatic weeds South Creek (Meandering Vertical) Hyacinth) • Management of stock impact on waterways (W) • Signifi cant vegetation community • Damaging access (stock mainly with some • Encourage adoption of sustainable land management (Cumberland Shale Plains Woodland; human access damage on public land) practices in riparian lands (E) Cumberland River Flat Forest) • Barriers to ecosystem functioning (weirs) • Manage human impacts at public recreation river access • High public recreation access • Flow extraction points and along foreshores (E,W) • Signifi cant irrigation water supply • Water quality • Aquatic habitat condition and connectivity improvement • Some community based • Future urban development will further disrupt (P,W) environment activity natural hydrology • Urban water quantity / fl ow management (I) • Water quality / nutrient management (I) Action Triggers • Increase community capacity for environmental • Rare or threatened river category (Meandering restoration (E) Vertical) • Severe downstream impacts (weeds, water quality) Ropes R1 Headwaters from Revegetation • High woody weed invasion • Revegetation with indigenous riparian vegetation (W) Cecil Park on • Modifi ed / engineered channel (stormwater • Removal/replacement of exotic riparian vegetation (W) Elizabeth Drive to structures) • Management of aquatic weeds confi ned section • Aquatic weed outbreaks (Salvinia; Water • Manage human impacts at public recreation river access Hyacinth) points and along foreshores (E,W) • Damaging access (human access points) • Aquatic habitat condition and connectivity improvement • Barriers to ecosystem functioning (P,W) • Flow extraction • Urban water quantity and fl ow management (I) • Water quality • Urban water quality and sediment management (I,W) • Lack of community based environment activity • Increase community capacity for environmental restoration (E) Action Triggers • Severe downstream impacts – water quality; weeds. 71 Appendix 4.2 Subcatchment summaries South Creek 72 72 Reach Management Recommendations – South Creek Subcatchment Reach Name Reach Riparian Land Reach Values Reach Threats Reach management recommendations Description Management (Planning, Education, Works, Monitoring, Institutional) Category Ropes R2 Concrete lined Revegetation • Fully engineered channel – concrete lined • Revegetation with indigenous riparian vegetation (W) channel from • Aquatic weed outbreaks (Salvinia; Water • Management of aquatic weeds Lincoln Rd Hyacinth) HAWKESBURY NEPEAN CATCHMENT MANAGEMENT AUTHORITY MANAGEMENT NEPEAN CATCHMENT HAWKESBURY HAWKESBURY NEPEAN CATCHMENT MANAGEMENT AUTHORITY MANAGEMENT NEPEAN CATCHMENT HAWKESBURY crossing to the • Flow extraction Sydeny Water • Water quality supply pipeline Action Triggers • Severe downstream impacts – water quality Ropes R3 Sydney water Assisted • Good riparian vegetation • Modifi ed / engineered channel • Removal/replacement of exotic riparian vegetation (W) pipeline crossing Regeneration • Rare or threatened river category • High woody weed invasion (Privet) • Increase community capacity for environmental to start of former (Meandering Vertical) • Aquatic weed outbreaks (Salvinia; Water restoration (E) ADI site just • Signifi cant vegetation community Hyacinth) • Management of aquatic weeds (I,W) above junction (Cumberland Shale Plains • Damaging access (Humans – bike tracks, 4WD •