Biodiversity Strategy - Gosford City Council - NSW Government

Gosford's ICOLLs present a range of management issues such as persistent algal blooms,
offensive odours and poor waterquality. Each ICOLL is under significant threat from urban
development and exhibit symptoms of nutrification. Avoca lagoon is the worst, followed by
Cockrone, Wamberal and Terrigal. Management actions and some general information on the
lagoons can be found in the Coastal Lagoons Management Plan (GCC, 1995a). All of the higher
priority management actions listed in the Plan have been completed and a thorough review of
the Plan is required.
Wamberal
Wamberal Lagoon is the most northerly of the four Gosford Coastal Lagoons, and has a small
part of the catchment in the Wyong Council area. The majority of the catchment lies to the north
of the lagoon and is largely undeveloped rural land. This main tributary of the lagoon is
commonly referred to as Forresters Creek and drains 2.6 square kilometres of the northern
catchment. South and west of the lagoon is the residential area of Wamberal. The north-eastern
part of the catchment consists of part of the suburb of Forresters Beach. Other tributaries of the
lagoon all have catchment areas totalling less than 50 hectares. The two largest enter the
lagoon through Wamberal Park from near Winston Street and Loxton Avenue.
Wamberal Lagoon itself is substantially protected by the Wamberal Lagoon Nature Reserve
which has been dedicated under the National Parks and Wildlife Act, 1974. The nature reserve
is subject to a Plan of Management administered by the Department of Environment and
Conservation (formerly National Parks and Wildlife Service). On the seaward side, the nature
reserve encloses the whole of the coastal barrier, whilst at other locations around the waterway
there is land of variable width affording some protective separation from other land uses. The
nature reserve provides suitable habitat for waterbirds, whilst the frontal dune carries an
example of a dunal plant succession valuable for educational purposes and not readily available
elsewhere near Sydney.
The existence of the nature reserve increases the protection from stormwater runoff from the
surrounding catchment into the lagoon. Wamberal Lagoon Nature Reserve includes reed beds,
sedgeland and important habitat for fish, molluscs, crustaceans and a range of migratory
waders identified in one or more international treaties. Wamberal Lagoon has recorded the most
diverse and abundant fish assemblages of those lagoons between the Hawkesbury River and
Tuggerah Lakes (Breen et al. 2005).
Terrigal
Terrigal Lagoon is an important recreational entity. At present two commercial tourist operators
use the lagoon; boat hire near the entrance and sailboard hire near the Willoughby Road
Bridge. Swimming at the lagoon entrance is also a popular activity for younger children.
Terrigal Lagoon is the most impacted of Gosford's ICOLLs and this is reflected by the lowest
water quality. A large part of the upper catchment area is rural land most of which has been
cleared. The lower slopes in the vicinity of the lagoon contain extensive urban development.
South and west of the lagoon is the township of Terrigal. The northern part of the catchment
includes part of the suburb of Wamberal. A large knoll of land rises from the centre of the
catchment separating the two arms of the lagoon into a North Arm and a West Arm. The
Country Club and Golf Course are located at the limit of the North Arm. This area is dissected
by a creek called North Arm Creek. The North Arm of the lagoon drains an area of 4.5 square
kilometres and the West Arm drains an area
of 3.7 square kilometres.
Avoca
Avoca has the next lowest water quality of Gosford's ICOLLs. Much of the upper catchment of
Avoca Lagoon is rural land, predominantly farmland or undeveloped forest. The lower slopes in
the vicinity of the lagoon contain significant urban development. To the immediate north and
Biodiversity - Technical Report Page 143