May 16, 2017

Lake Cowal in the last flood

Report by Malcolm Carnegie,

Photography by Malcolm Carnegie

Projects Manager – Lake Cowal Foundation

Commencing in late June 2016, flooding rains over much of inland NSW through to the end of October 2016 saw the Lachlan River and Bland Creek  fill Lake Cowal to a flood peak equivalent to that of 1990.

A flooded Bland Creek looking north to Lake Cowal

Once full, water flows from the north of Lake Cowal near Bogies Island into Nerang Cowal. From here, the Manna and Bogandillon Creeks flow into the Bogandillon Swamp and ultimately back into the Lachlan River.

Black Swans

When full, Lake Cowal covers an area of approximately 13,000 hectares with a length of 21 kilometres by 9.5 kilometres at its widest point, having a maximum depth of 3.5 metres, and taking a period of up to three years to dry mostly through evaporation, provided no significant inflows occur.

During the Spring/Summer/Autumn of 2016/17 a variety of waterbirds took the opportunity to breed in both the lignum areas and fringing river red gums of the lake. Species feeding and/or breeding in the various habitats of the lake included:

• Royal Spoonbill and Yellow-billed Spoonbill;
  

  Royal Spoonbill

• White-necked Heron and White-faced Heron;
• Nankeen Night Heron;
• Great Egret;
• Little Black Cormorant, Little Pied Cormorant and Pied Cormorant;
• Australasian Darter;
• Eurasian Coot;
• Australasian Grebe and Great Crested Grebe;

Red-necked Avocets

Juvenile Nankeen Night-Heron

• Red-necked Avocet;
• Black Swan;
• White-headed Stilt;
• Whiskered Tern;
• Sacred Kingfisher;
  

  Sacred Kingfisher

• Plumed Whistling Duck, Pink-eared Duck, Blue-billed Duck, Chestnut Teal and Pacific Black Duck;

• 

  Plumed Whistling-Ducks

  

  Straw-necked Ibis

• Australian White Ibis, Straw-necked Ibis and Glossy Ibis;

• Magpie Goose observed and breeding for the first time since 1990.

Magpie Geese

White-necked Heron

Presently approximately 2,000 Australian Pelicans are fishing the shallower northern sections of Lake Cowal with the water level presently relatively stable through the winter months. With no further inflows, the lake is expected to have water in it through to the 2018/19 Summer.

Pelican-rookery; Nimmie-Caira

Pelican-rookery-Feb-17-Nimmie-Caira

Pelican rookery photographs were taken by by Vince Bucello at Nimmie Caira.