41-603: Rocky Creek may refer to: Australia [ edit ] Rocky Creek Dam , a water catchment dam on the North Coast of New South Wales, Australia Rocky Creek, Queensland , a locality in the Toowoomba Region United States [ edit ] Rocky Creek, Florida , an unincorporated community in Hillsborough County Rocky Creek (Oregon) ,
82-491: 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 NSW National Parks & 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
123-805: A coastal stream in Lincoln County Rocky Creek (Current River) , a stream in Missouri Rocky Creek (South Carolina) , a tributary of the Broad River (Carolinas) Rocky Creek (Texas) , a stream in Victoria County Rocky Creek (Wisconsin) , a stream in Wisconsin Rocky Creek Bridge (California) , a bridge in Monterey County Rocky Creek Bridge No. 01089 , a highway bridge along
164-625: A great extent that Prime Minister Ben Chifley approved the formation of the National Mapping Council of Australia in 1945 with a primary objective of planning and managing the nation's topographic mapping activities. The inaugural National Mapping Council consisted of the Director of National Mapping, the Commonwealth Surveyor General and respective State Surveyors-General. The council's first meeting held discussions between
205-528: 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
246-522: A new Australian vertical datum. Prior to the creation of the Australian Height Datum, levelling surveys were carried out by professional surveyors for construction and mapping purposes using only local or state-based vertical datums. The execution of military operations across the Australian mainland during World War II heavily exposed the lack of Australian topographic mapping , to such
287-476: Is 31 square kilometres (12 sq mi) 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 730 cubic metres per second (26,000 cu ft/s). The vegetation in the catchment
328-641: Is called Rocky Lake . 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 25 kilometres (16 mi) 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
369-594: Is different from Wikidata All article disambiguation pages All disambiguation pages Rocky Creek Dam Rocky Creek Dam is a minor rock fill clay core embankment dam across the Rocky Creek, located upstream of Lismore in the Northern Rivers region of New South Wales , Australia . The dam's main purpose is to supply potable water for the region, including Lismore, Ballina , Byron Bay , Evans Head and Alstonville . The impounded reservoir
410-604: 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 or associated with the Tweed Volcano . The subtropical rainforest is generally regarded as one of the biggest remnants of the Big Scrub rainforest that once existed over
451-516: 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
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#1732895246848492-541: The 1970s, the Australian Height Datum was constructed using a lower standard of spirit-levelling equipment and techniques to ensure completion in the shortest possible period of time. For example, approximately 80% (76520 km) of the primary levelling contributing to the Australian National Levelling Network was completed by private contractors during the 10-year period from 1960 to 1970. Since then, significant errors have been identified including
533-557: The AUSGeoid09 model is able to “practically” eliminate the north–south error when converting GNSS readings to Australian Height Datum heights. The Australian Height Datum ( Tasmania ) is considered as a separate datum to the Australian Height Datum, consisting of a least-squares adjustment of seventy-two levelling sections across the Tasmanian state, while simultaneously assigning the mean sea level of two tidal gauges at Hobart and Burnie
574-542: The Australian Height Datum surface was derived and officially adopted in 1971 as the benchmark to which all new vertical height measurements in Australia are referenced to. Since the inception of the Australian Height Datum in 1971, numerous deficiencies, distortions, offsets and other errors have been identified and examined using newer technologies. Due to Australia's desperate need for a surveying vertical control and accurate topographic mapping for mining exploration during
615-469: The Australian Height Datum: the datum surface has a gradient of zero (i.e. perfectly horizontal). While this systematic error is relatively insignificant for the design of “small-scale engineering projects” that use local heights, the north–south slope is very influential on the design of “large-scale studies” that span larger distances across the country. The north–south slope is primarily due to
656-413: The Australian National Levelling Network that were used to determine the Australian Height Datum, each utilising their own levelling parties that conducted a combination of one-way and two-way levelling. These levelling parties consisted of two drivers of separate vehicles, as well as one instrument man who would alternate between the cars as they "leap-frog along the levelling route". This strategy involved
697-588: The Interior Hydro-Electric Authority One-Way Levelling Two-Way Levelling Sea level data from thirty tidal gauges positioned around the Australian mainland coastline was also collected in order to derive the Australian Height Datum. The distances between each successive tidal gauge varied significantly around the country, with the smallest interval between Port Kembla to Camp Cove (128 km) and
738-662: The National Mapping Council of Australia in July 1971. The Australian Height Datum is the vertical height of 0.000m established within the Australian National Levelling Network (ANLN), through taking the mean sea level of 30 tide gauges along the entire Australian coastline during the period of 1966–1968. The datum surface is based upon a least squares adjustment of the original, ‘primary’ levelling data spanning 97,320 km, combined with more recent, ‘supplementary’ levelling data spanning 80,000 km. Five different observing authorities contributed to primary levelling sections in
779-601: The Oregon coast See also [ edit ] Rock Creek (disambiguation) [REDACTED] Topics referred to by the same term This disambiguation page lists articles about distinct geographical locations with the same name. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Rocky_Creek&oldid=1001958765 " Category : Place name disambiguation pages Hidden categories: Short description
820-416: The Rous County Council. The dam wall is made up of about 80,000 tonnes (79,000 long tons) of rock, soil, clay and concrete and is 28 metres (92 ft) high and 220 metres (720 ft) long. At 100% capacity the dam wall holds back 14,000 megalitres (490 × 10 ^ cu ft) of water at 187 metres (614 ft) AHD . The surface area of Rocky Lake is 200 hectares (490 acres) and the catchment area
861-546: The addition of the Northern Territory and Queensland state authorities. To assist mining companies with the search for oil during the 1960s, the Federal Government made additional funds available to the Director of National Mapping to employ private contract surveyors to speed up the surveying effort. By 1970, the consolidation of levelling and tide gauge data from these collective surveying operations resulted in
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#1732895246848902-404: The catchment area. Australian Height Datum The Australian Height Datum was introduced in 1971 as the official vertical datum for Australia, and thereby serves as the benchmark to which all height measurements are referred. The Australian Height Datum is an amalgamation of decades of spirit levelling work conducted by numerous state and territory authorities across the country, and
943-686: The entire of the Australian continent ; an activity later named the Australian Levelling Survey. From 1945 to 1955, the New South Wales , Victorian and Western Australian state authorities, with assistance from the Royal Australian Survey Corps , commenced the Australian Levelling Survey by levelling 4,800 km of the mainland. By 1960, 20,800 km of controlled levelling had been completed with
984-399: The establishment of the two datums, the mean sea levels for the mainland and Tasmanian datums are highly likely to contain some degree of error relative to the true mean sea level value. This neglection of the differences in ocean's time-mean dynamic topography between the creation of Australian Height Datum (mainland) and Australian Height Datum (Tasmania) resulted in a distinct offset between
1025-414: The fact that the Australian Height Datum was taken as the fixed mean sea level of 30 tide gauges around Australia over a 2-year period, ignoring the natural variations in sea-surface topography . The National Mapping Council of Australia chose to use this ‘mean sea level’ approach to minimise the use of negative heights, that are quite problematic for surveyors and engineers, near coastal areas where most of
1066-503: The formation of a 97,320 km "single homogenous network" of primary levelling spanning the entire country, named the Australian National Levelling Network . Through the linear adjustment of 757 primary levelling sections across the Australian National Levelling Network, while simultaneously "holding 30 tide gauges fixed at their mean sea level values", the Australian Height Datum was determined and then adopted by
1107-427: The formation of a distinct 1.5m North-South slope within the Australian Height Datum. In order to counteract this slope, the AUSGeoid09 gravimetric quasigeoid model has been introduced to determine Australian Height Datum heights from Global Navigation Satellite System (GNSS) readings. As GPS heights provide a far greater limit of reading that the magnitude of the spirit-level errors in the Australian Height Datum,
1148-476: The height of the mainland and Tasmania datum surfaces , estimated to be between −61 mm and +48 mm. In addition to the north–south slope, numerous other regional distortions within the Australian Height Datum have been identified across the state of Western Australia. The largest of these non-linear distortions are present across the Goldfields-Esperance and northern Kimberley regions. Unlike
1189-411: The instrument man taking both a back sight and fore sight staff reading, before being driven by one of the drivers, past the other driver's stationary car, to the next set-up position to take the next set of reading. The two drivers’ responsibility was to hold the levelling staffs , while the instrument man would operate the level and record the readings in a level book. By employing this strategy,
1230-466: The largest interval between Point Lonsdale to Port Kembla (1,150 km). Sea level observations were conducted on an hourly basis from 1 January 1966 to 31 December 1968 for 29 of the designated tidal gauges, and from 1 January 1957 to 31 December 1960 for the single tidal gauge at Karumba , Queensland . Once all the tidal data was collected and processed, the Port MacDonnell tidal gauge station
1271-458: The levelling parties were able to achieve an average of 35 km of primary levelling each day. One-way levelling involved adopting this outlined methodology in only one direction, while two-way levelling also would repeat this again in the opposite direction to improve the accuracy of the readings. The following outlines the cumulative contribution of the levelling parties for their respective observing authority: (Combined) National Mapping
Rocky Creek - Misplaced Pages Continue
1312-494: 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 near Lismore treating it at an upgraded Nightcap Water Treatment plant at Rocky Creek Dam. The emergency Wilsons River source
1353-465: The north–south slope of 1.5m, offset between Australia mainland and Tasmania of 26 cm, as well as regional distortions throughout Western Australia. The North-South Slope is a systematic error in the Australian Height Datum's horizontal surface of approximately 1.5m from the North coast to South coast of Australia. This tilt is quite problematic, as it invalidates the major assumption in using
1394-431: The population resides. By utilising the mean sea level approach, the creation of the Australian Height Datum neglected the significant influence the ocean's time- mean dynamic topography on the fluctuations in sea surface levels around the country. Spatial variation of sea level change , freshwater outflow in harbour areas where tide gauges are positioned, and an amalgamation of ocean dynamics have all contributed to
1435-415: The respective state authorities about the need to have a unified national scheme for surveying and mapping of Australia. Upon the meeting's completion, members of the National Mapping Council of Australia unanimously agreed that the Director of National Mapping, Frederick Johnston , would be tasked with the coordination of local, state and Commonwealth authorities in order to execute mapping activities across
1476-405: The vertical height of 0.000m over the year of 1972. This method deviates from the method employed to determine the mean sea level used to create the mainland Australian Height Datum, which was taken across the period from 1966 – 1968 for 29 of the tidal gauges and 1957-1960 for the single tidal gauge at Karumba . By employing inconsistent approaches to the study period of the mean sea level during
1517-400: 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 clay core, followed by replacement of the gravel and road over the dam wall. Water from the lake
1558-474: The well-defined and measurable north–south tilt across the state, the linear regression of these distortions does not lend itself to any distinct trends. Moreover, the utilising gravimetric quasigeoid models to “practically” eliminate the impact of the ocean's time-mean dynamic topography does not minimise the extent of these regional distortions. For these reasons, the regional distortions throughout Western Australia are attributed to random errors “present in
1599-422: Was completed in 2003 and the fully developed Wilsons River source and upgrade of the Nightcap Water Treatment Plant was completed in 2008. 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
1640-411: Was corrected to align with the mean sea level observations of thirty tide gauges positioned around the entire coastline. While it remains the published vertical datum for all surveying and engineering operations performed throughout Australia , newer technologies have uncovered numerous deficiencies, offsets and distortions within the Australian Height Datum, leading to discussions about defining
1681-467: Was selected to be the “nominal origin” and the station's mean sea level was assigned a value of 0.000 m. Zero condition equations between Port MacDonnell and the other 29 stations’ sea level data were then utilised to hold the mean sea level at 0.000 m across the entire national tide gauge network, while the primary and secondary levelling records within the Australian National Levelling Network were simultaneously adjusted to fit this model. In doing so,