| Rocky Creek Dam | |||
|---|---|---|---|
| Rocky Creek Dam | |||
| Lake type | reservoir | ||
| Primary inflows | Rocky Creek and Gibbergunyah Creek | ||
| Primary outflows | Rocky Creek | ||
| Catchment area | 31 km2 (12 sq mi) | ||
| Basin countries | Australia | ||
| Built | 1953 | ||
| First flooded | May 1953 | ||
| Surface area | 2 km2 (0.77 sq mi) | ||
| Water volume | 14,000 ML | ||
| Surface elevation | 187 m (614 ft) | ||
Rocky Creek Dam is a drinking water catchment dam on the North Coast of New South Wales, Australia. The dam forms the waterbody known as Rocky Lake. As the principal source for Rous Water it supplies water for the majority of the Far North Coast of New South Wales including Lismore, Ballina, Byron Bay, Evans Head and Alstonville.
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The Rocky Creek Dam catchment is made up of 31 km²[1] 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 for the North Coast of New South Wales.
The vegetation in the catchment is mainly subtropical rainforest or wet sclerophyll. 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 and thick rhyolite rocks erupted from the Tweed Volcano. 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 itself covers around two square kilometres (478 acres) and can hold about 14,000 mega litres of water when at 100% capacity. The dam wall is 28 metres high and is made up of about 80,000 tonnes of rock, soil, clay and concrete. Construction of the dam and spillway was completed in 1953.
In 2009 the dam wall was upgraded. This upgrade did not increase the height of the dam wall or increase the volume of water stored behind the dam, it was focused on 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 clay core, followed by replacement of the gravel and road over the dam wall. Actual construction works took approximately three months.
Recreation (including swimming and boating) on the lake itself is prohibited to protect the high quality of the water in the dam. However, a recreational area is provided by Rous Water near the dam wall including lawns, barbecues, playgrounds, walking tracks (including a board walk and pontoon bridge) 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 National Parks and Wildlife Service as National Parks 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.
Water from the lake is used as a potable water supply by Rous Water 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.