Locke Swamp Floodgates

Statement of Significance

The Locke Swamp Floodgates are important to the people of Busselton as they were a vital component in creating larger areas of arable land which assisted in the agricultural development of the district.
The construction of the floodgates demonstrates the importance that the government placed on the conversion of swampy land, which was constantly inundated by saltwater, into productive arable land. The Locke Swamp Floodgates were part of an extensive drainage programme in the South West which was first implemented in the 1910s.
The Locke Swamp Floodgates are associated with the development of
Busselton as an important agricultural district in the South West. The
Locke Swamp Floodgates represent a technology which is no longer practised due to the high maintenance requirements of the various components.

Physical Description

This place was not visited in this 2024 review. The following description is drawn from the 2013 review. The Locke Swamp Floodgates are located approximately 100 metres to the south of Caves Road in a flat, natural environment. Vegetation on either side of the drain is dominated by native peppermint trees (agonis flexuosa) with smaller understorey plants.
The timber structure extends across the width of the drain which is approximately 8.5 metres wide. The sloping sides of the banks have been covered with stones and the plans indicate stones were also used to line the bottom of the drain around the gates. However, due to the depth of water it was not possible to determine if these stones were still
present. The main structural components are the nine, 30cm diameter timber piles which stretch across the width of the river at approximately 2 metre intervals. These, together with an additional five piles placed upstream of the main row, provide the structural base to which the gate components have been added. The five upstream piles provide bracing
support for the downstream piles. The four gates are positioned across the width of the ditch, low down near the bottom of the ditch. Vertical timber boards (whaling), using birdmouth sheeting to provide water tightness, extend out from each bank to approximately the bottom edge of the ditch. The four gates have then been evenly spaced
across the width of the ditch between the whaling. Timber boards create a sill at the bottom of the ditch, directly beneath the gates. The gates are constructed with vertical timber boards which are attached to a steel frame. The gates are hung on the
downstream side of the structure. A hinged component on the boards permits the gates to open when freshwater flows down the ditch, but when saltwater runs back up the ditch they are forced shut. Each gate has been equipped with a lever which is two steel bars, set at either end of the gate, which stretch up above the level of the pylons and
are joined across the top with a steel bar. Hinges placed at the level of the pylons and also down near the top of the gate permit the gates to be hinged open if required. The top section of the hinge (which is at the same level as the tops of the pylons), is secured to timber cross pieces which formerly supported timber boards which ran across the width of the gate structure. Above the gates, horizontal boards close the gap between the vertical whaling, thus preventing saltwater entering the ditch.

History

Several rivers ran through this area: the Vasse, Abba, Sabina, New and Lennox. Often in the winter time these rivers would spread out over the low lying areas before finding their own way to the sea. Whilst the swampy nature of the area had initially attracted the first settlers, it was soon realised that larger areas of land could be brought under cultivation if only they could be drained and the detrimental effect of saltwater contamination (most problematical during the winter months), controlled. One of the first attempts at draining the land was made by Captain John Molloy sometime during the 1850s. The Lennox River, which flowed through his land, was originally prevented by sandbanks from flowing into the sea. Molloy made a cut between the river and the shore to allow the river to flow out to sea. This cut became known as “Molloy's Ditch”.

The Land Drainage Act was passed by Parliament in 1900, amendments to the Act were made in 1902 and 1904. Following this Act, a number of drainage programmes were implemented throughout the South West. The creation of the Lennox Drainage District was approved in March 1910. This district covered land to the west and south of Busselton and included the New and Lennox Rivers. The Drainage District was governed by a Board comprising six elected members. Three of these members later resigned eading to the Board becoming unconstitutional. The settlers constructed a cut across the New River in 1914 and constructed floodgates across the cut to prevent saltwater flowing
back down the new drain. As the cut crossed the main road to Yallingup (now Bussell Highway), the floodgates were attached to the new road bridge. However, the Board ran into difficulties when it attempted to collect rates (to pay for the construction of the gates and drain), from settlers living in the Lennox Drainage District. One of the settlers
successfully took the Board to court which ruled that the Board was unconstitutional as it only had three members. This decision meant that as there was no Board, there was no authority to pay for the upkeep of the gates. Over the years, this legal problem led to the settlers sending numerous complaints about the condition of the gates to the Department of Water, Sewerage and Drainage who invariably replied that until the settlers appointed six members to the Board, it was not Perth’s problem.

The provision of the ditch enabled the water to drain away thereby creating arable farmland. Flooding in the winter was also minimised by the ditch and floodgates, which were constructed near the ditch's exit point at Geographe Bay. The floodgates not only stopped saltwater running up the ditch at high tide (or during rough weather) and
contaminating the valuable farming land with salt, but they also allowed any floodwaters to flow out into the Bay.

In 1919, the district engineer recommended that repairs needed to be made before they were undermined. Approval was finally given in February 1920 for £150 to be made available to repair the gates. At the same time, the Sussex Roads Board (later City of Busselton), wrote requesting that the Public Works Department complete the drainage
works in the by upgrading and widening the ditch. This would enable more land to be drained and also extend the carrying capacity of the higher land nearby. In 1921, the Department of Water, Sewerage and Drainage, authorised a survey of the area to determine how best to drain the area. By March 1921, the surveys had been completed and in December 1922, plans for a new set of floodgates and road bridge were drawn up. The new gates and bridge were completed by June 1923.

In 1947, new plans were drawn up to build a new set of floodgates on the drainage ditch. These were set back approximately 200 metres from the main road and the 1923 floodgates. The new gates were completed by 1948. The plans show that the piles, bracing, whaling boards and timber superstructure was all constructed from jarrah. The four flood gates were to be constructed using a steel frame which was then clad with Oregon planks. Oregon was considered to be the most resist to sea worm attack. Pairs of foot planks (jarrah), extended across the top of the structure to permit pedestrian access across the gates.

The gates which remain insitu across the cut appear to be exactly the same as those constructed in 1948, with the exception of the paired foot planks which are now missing. Photographs of these gates in January 2002, show these boards were still in place at this time.

Integrity/Authenticity

High Degree/High Degree
Integrity Notes: High – historic use remains unchanged.
Authenticity Notes: Locke Swamp Floodgates have retained a high degree of authenticity.

Condition

Good

Uses

Historic Themes

Creation Date

Publish place record online (inHerit):

Last Update

Disclaimer

This information is provided voluntarily as a public service. The information provided is made available in good faith and is derived from sources believed to be reliable and accurate. However, the information is provided solely on the basis that readers will be responsible for making their own assessment of the matters discussed herein and are advised to verify all relevant representations, statements and information.