Lower Manorburn Dam Margins

Description: Lower Manorburn Dam Margins

Type/Class: Swamp 2

Size: 18.4 ha

Altitude: 160-180 m above sea level

Approximate location: 1.7 km Southeast of the intersection of Lower Manorburn Dam Road and Galloway Road, Alexandra |NZTM (centre point): E1321600 N4984100

Regional Plan: Water for Otago| Schedule 9 Regionally Significant Wetland, no.88, Map F13

Territorial Authority: Central Otago District Council

Recorded Values:

Value

Description

A1

Habitat for nationally or internationally rare or threatened species or communities. Little Shag (Phaacrocorax melanoleucos brevirostris) has been recorded at this site Little Shag is classified as At Risk-Naturally Uncommon in Miskelly et al. (2008). 102

A5

Scarce in Otago in terms of its ecological or physical character. Less than 15% of swamps remain in Otago. 2 Located in Manorburn Ecological District where c. 2% of land cover comprises lakes and ponds and herbaceous freshwater vegetation. 102

A2 - A4, A6 - A9

No relevant information is currently held by the ORC.

 

Other Information:

  • The margins of the Lower Manorburn Dam contain lacustrine swamp vegetation dominated by crack willow (Salix fragilis) over raupo (Typha orientalis), as well as swamp vegetation where raupo is dominant. 2 , 102

  • Common associate species were Juncus articulatus, duckweed (Lemna minor), Carex secta, and Azolla filiculoides, with alder (Alnus glutinosa) near the main car park. Open water and mud were also present. 102

  • Other species recorded were Glyceria fluitans, Ranunculus trichophyllus and water forget-me-not (Myosotis laxa subsp. caespitosa). 102

  • At the eastern (upper) end of the reservoir, the crack willow canopy is only interrupted by open water. Reservoir margins in this area contain crack willow over sweet brier (Rosa rubiginosa), Coprosma propinqua, and a few rowan (Sorbus aucuparia). 102

  • The ground is covered in cocksfoot (Dactylis glomerata), tall fescue (Schedonorus phoenix), water celery (Apium nodiflorum), and Californian thistle (Cirsium arvense). 102

  • Six native bird species were recorded at the site. These include New Zealand Shoveler (Anas rhynchotis variegata), New Zealand Scaup (Aythya novaeseelandiae), Australasian Harrier (Circus approximans), Australian coot (Fulica atra), Grey Warbler (Gerygone igata) and Little Shag (Phalacrocorax melanoleucos brevirostris). 102

  • Seven exotic bird species were recorded at the site. These include Mallard (Anas platyrhynchos), Goldfinch (Carduelis c arduelis), Greenfinch (Carduelis chloris), Redpoll (Carduelis flammea), Yellowhammer (Emberiza citrinella), Chaffinch (Fringilla coelebs) and Song Thrush (Turdus philomelos). 102

  • Listed as an Additional Wetland in Schedule 19.6A of the Central Otago District Plan. 55

 

Aerial View of Lower Manorburn Dam Margins (March 2005)

 

 

Lower Manorburn Dam

 

References:

2 Ausseil, A.G., Newsome, P., Johnson, P. (2008) Wetland Mapping in the Otago Region. Landcare Research Contract Report prepared for the Otago Regional Council.

55 Central Otago District Council (2008) Central Otago District Plan, Published by Central Otago District Council, Alexandra.

102 Wildland Consultants (2011) Ecological evaluation of seven wetlands in relation to proposed Plan Change 2, Regional Plan water for Otago. Report prepared for Otago Regional Council.