Rocky Creek Dam is a minor rock fill clay core embankment

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

across the Rocky Creek, located upstream of Lismore in the Northern Rivers region of

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. The dam's main purpose is to supply

potable water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, ag ...

for the region, including Lismore, Ballina, Byron Bay,

Evans Head Evans Head is a town in Richmond Valley Council of the Northern Rivers region of New South Wales, Australia. At the 2016 census, Evans Head had a population of 2,843 people. It is 726 kilometres north of Sydney, and 11 kilometres east off the ...

and Alstonville. The impounded

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

is called Rocky Lake.

Location and features

Commenced in 1949 and completed in April 1953, the Rocky Creek Dam is a minor dam located in the Northern Rivers region of New South Wales, situated approximately north of Lismore. The dam is the principal component of the Rous County Council bulk supply network for the region, experiencing population growth. The dam was built by Dayal Singh under contract to the Rous County Council. The dam wall is made up of about of rock, soil, clay and concrete and is high and long. At 100% capacity the dam wall holds back of water at AHD. The surface area of Rocky Lake is and the catchment area is which includes the Whian Whian State Forest, Nightcap National Park and Whian Whian State Conservation area. The area was once used for logging but is now has a conserved and generally pristine catchment environment. The uncontrolled spillway is capable of discharging . The vegetation in the catchment is mainly subtropical rainforest or

wet sclerophyll Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...

. The vegetation community generally reflects the geology and soils in the area which are derived from the Lamington Volcanics which in this area consists of

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

and thick

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

rocks erupted from or associated with the

Tweed Volcano Tweed Volcano is a partially eroded Early Miocene shield volcano located in northeastern New South Wales, which formed when this region of Australia passed over the East Australia hotspot around 23 million years ago. Mount Warning, Lamin ...

. The subtropical rainforest is generally regarded as one of the biggest remnants of the Big Scrub rainforest that once existed over a large part of the surrounding region. The dam is considered small compared to the size of the population it services. However, the secure yield is high because of the catchment's climate with its consistent high annual rainfall. The nearby Rummery Park rain gauge formerly operated by the Bureau of Meteorology has the highest average annual rainfall in New South Wales. However, in 2003 the lack of rain meant that the water level was at one stage less than twenty per cent. In 2009 the dam wall was upgraded by ensuring the safety of the dam wall during a maximum probable flood. The upgrade involved the removal of the top of the wall, the installation of a concrete cut-off wall keyed into the

impermeable Permeability, permeable, and semipermeable may refer to: Chemistry *Semipermeable membrane, a membrane which will allow certain molecules or ions to pass through it by diffusion *Vascular permeability, the movement of fluids and molecules betwe ...

clay core, followed by replacement of the gravel and road over the dam wall.

Water supply

Water from the lake is used as a potable water supply by Rous County Council to the region. It is the primary water source to the centres of Alstonville, Ballina, Byron Bay, Evans Head, and Lismore. Water is pumped from the lake a short distance to the Nightcap Water Treatment Plant and then this water is provided to the region generally through gravity reticulation. The water available from the Rocky Creek Dam is usually considered very reliable because of the nature of the catchment and the areas climate. However, in 2003 the water level at the dam dropped below 20% and the region was subject to severe water restrictions. Because of this it was decided by Rous County Council to augment the Rocky Creek Dam supply by developing another source on the

Wilsons River Wilsons River, a perennial river and part of the Richmond River catchment, is situated in the Northern Rivers district of New South Wales, Australia. Course and features The river rises on the eastern slopes of Jerusalem Mountain within the Ni ...

near Lismore treating it at an upgraded Nightcap Water Treatment plant at Rocky Creek Dam. The emergency Wilsons River source was completed in 2003 and the fully developed Wilsons River source and upgrade of the Nightcap Water Treatment Plant was completed in 2008.

Recreation

Recreation (including swimming and boating) on Rocky Lake is prohibited to protect the high quality of the water in the reservoir. However, a recreational area is provided by Rous County Council near the dam wall including lawns, barbecues, playgrounds, walking tracks (including a board walk and

pontoon bridge A pontoon bridge (or ponton bridge), also known as a floating bridge, uses float (nautical), floats or shallow-draft (hull), draft boats to support a continuous deck for pedestrian and vehicle travel. The buoyancy of the supports limits the maxi ...

) and interpretive walks. The lawns near the edge of the lake are often used for weddings. The catchment is mainly under the control of the NSW National Parks & Wildlife Service as

national parks A national park is a natural park in use for conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual ...

and State conservation areas. This means that only passive recreation such as bush walking, bird watching, etc. are permitted. However, swimming, boating, 4WD and dirt bikes are prohibited in the catchment area.

References

External links

Rous
County Council {{Northern Rivers region , state=autocollapse Dams in New South Wales Dams completed in 1953 Northern Rivers Embankment dams 1953 establishments in Australia

Location and features

Water supply

Recreation

See also

References

External links