Merrimu Reservoir is located on Pyrites Creek at Coimadai in the Shire of Moorabool, 10km north east of Bacchus Marsh. Pyrites Creek is a tributary of Werribee River. The reservoir has a storing capacity of 32,000ML and was constructed in three stages from 1969 to 1986 to supply drinking water to Melton and Bacchus Marsh. Excess water is diverted for irrigation in the Werribee irrigation district.
Lerderderg Weir diverts water from the Lerderderg River though a four-kilometre tunnel into Goodmans Creek. A portion of the resultant combined flow in Goodmans Creek is then diverted at Goodmans Weir via a 1.6km long tunnel into Pyrites Creek just above Merrimu Reservoir. Construction of these diversion works has enabled Merrimu reservoir to be provided with adequate flows.
Water released from Merrimu Reservoir flows down Pyrites’ creek to Melton Dam and subsequently down to Werribee irrigation district. The pumping station below the dam lifts water via pipelines to the urban areas of Bacchus Marsh and Melton.
Merrimu Reservoir park is also home to war memorial to honour the fallen soldier of the World War.
History of Coimadai Valley
The township of Coimadai was established in the 1850’s after rich lime deposits were discovered in the valley. The name Coimadai in aboriginal language means, ‘’The Oldman Kangaroo Resting’’.
By the mid 1850’s four lime burning Kilns were in production and some twenty families lived in the area. At its peak around 100 men were engaged in the lime burning industry. By the 1920’s numbers had reduced to 30 and by the 1930’s only half of it remained.
Lime industry created a number of associated industries which gave employment to the small community. Wood was cut and hauled into kilns, lime was quarried nearby, the kilns loaded and fired, lime was crushed bagged and carted. Although lime crushing continued until 1986, lime burning ended in the 1950’s as cement took over building construction. Agriculture lime also known as dolomite produced without burning process was continued until inundation of the dolomite pits by Merrimu reservoir.
The township consisted of Foresters Arms Hotel, a bush hotel established in the 1860’s. Coimadai School No 716 was established in 1863. In 1926, a community hall was built which subsequently burnt down in 1937. It was reconstructed and later moved to Grant Street at Bacchus Marsh.
The Valley also developed as a farming community with sheep, beef and diary, cattle and cereal crop production. Another landmark of Coimadai was mineral springs, which during the last century was famous internationally. A Mr Bower is said to have entered a sample of water in the 1880 Paris Exhibition, winning a gold medal. In 1936, a company was formed to bottle the water. A shortage of bottling supplies during the World War II forced the company to close.
Apart from the school and the home of Bennett family, the only remaining landmark of the old township were the lime Kilns, last of which were flooded with the enlargement of Merrimu reservoir in 1986.
After quarrying the limestone and wood was placed in the kilns in layers. Large wood was placed in the kilns first, forming a platform one to two metres high. Alternate layers of limestone and wood were then loaded until the kilns were full.
The wood was fired and a heat of 940 degree centigrade had to be reached to separate the carbon dioxide from the calcium in the limestone. As the wood burned the limestone dropped down the kiln and was drawn out the bottom by shovel for loading into crushing machine.
The fine lime was loaded into bags and stored or transported to Bacchus Marsh to the railway. Wagons piled high up with upto 250 bags of lime were a familiar sight in Coimadai. More than six horses were needed to pull the heavy wagons out of the valley. Once the hill had been negotiated, two horses were unhitched to make their own way back to Coimadai.
The rural water commission commissioned a number of investigations on the history and significance of the remains of the lime burning kilns before the last one was inundated by the waters of enlarged Merrimu Reservoir. The results are published in three separate volumes and are available at local libraries.
Address: Merrimu Reservoir Picnic Area, Coimadai, VIC 3334
Facilities available: Picnic tables, BBQ, Toilets
Dogs allowed on lead
Park and picnic areas should be used only between 8:30 am to 4:30pm
All flora and fauna in the park are protected.
Do not camp overnight here.
This is a closed catchment and reservoir, and all water activities are prohibited.
All the information provided here are collected from Merrimu Reservoir Area.