Six Mile Creek Dam

Six Mile Creek Dam
Six Mile Creek Dam spillway in 2021
Location of the Six Mile Creek Dam in Queensland
Country	Australia
Location	South East Queensland
Coordinates	26°22′52″S 152°55′48″E / 26.38111°S 152.93000°E / -26.38111; 152.93000
Purpose	Potable water supply Recreation[1]
Status	Operational
Opening date	1965 (1965)
Operator(s)	SEQ Water
Dam and spillways
Type of dam	Embankment dam
Impounds	Six Mile Creek
Height	15.7 m (52 ft)[1]
Length	490 m (1,610 ft)[1]
Dam volume	69×10^3 m3 (2.4×10^6 cu ft)[1]
Spillway type	Uncontrolled
Spillway capacity	1,147 m3/s (40,500 cu ft/s)[1]
Reservoir
Creates	Lake Macdonald
Total capacity	8,018 ML (1.764×109 imp gal; 2.118×109 US gal)[2][3]
Catchment area	49 km2 (19 sq mi)[1][2]
Surface area	260 ha (640 acres)[2][3]
Website www.seqwater.com.au

The Six Mile Creek Dam (more commonly known as Lake MacDonald) is a rock and earth-fill embankment dam with an un-gated spillway across the Six Mile Creek that is located in the South East region of Queensland, Australia. The main purposes of the dam are for potable water supply of the Sunshine Coast region^[3] and for recreation.^[1] The impounded reservoir is called Lake Macdonald, named in memory of former Noosa Shire Council Chairman Ian MacDonald.^[4]

The dam is located 6 kilometres (3.7 mi) from Cooroy and 15 kilometres (9.3 mi) west of Noosa. The small settlement of Lake MacDonald is located adjacent to the dam. The primary inflow of the reservoir is Six Mile Creek.^[3]

Built in 1965^[1] and raised by 3.6 metres in 1980, the rock and earthfill dam structure is 15.7 metres (52 ft) high and 490 metres (1,610 ft) long. The 69-thousand-cubic-metre (2.4×10^⁶ cu ft) dam wall holds back the 8,018-megalitre (1.764×10⁹ imp gal; 2.118×10⁹ US gal) reservoir when at full capacity. From a catchment area of 49 square kilometres (19 sq mi) that includes much of the Tewantin National Park, the dam creates Lake Macdonald, with a surface area of 260 hectares (640 acres). The uncontrolled un-gated spillway has a discharge capacity of 1,147 cubic metres per second (40,500 cu ft/s).^[1][5] Initially managed by the Sunshine Coast Regional Council, management of the dam was transferred to Seqwater on 1 July 2008.

The dam reached its maximum recorded level of 1.97m over the spillway in February 2012.^{[citation needed]}

In May 2019, Seqwater proposes to upgrade Six Mile Creek Dam (also known as Lake Macdonald Dam) as part of its Dam Improvement Program.^[6]

Within proximity of the dam, horse riding, boating and canoeing are permitted. The Noosa Botanic Gardens are located on the northwestern shoreline of Lake Macdonald.

The reservoir is stocked with Mary River cod, bass, yellowbelly, saratoga and snub nosed gar with endemic populations of tandans (eel tailed catfish) and the introduced spangled perch.^[3][7] A stocked impoundment permit is required to fish in the dam.^[8]

Historical high water capacity percentages above 110% since recording began on 1 July 2008.^[9]

• List of dams in Queensland