PHOTO: Jan Wood, who lives on the corner of Yarran and McMahon Street, was less than impressed to find her front yard flooded on Sunday.
THE OVERFLOWING of the Castlereagh River on Sunday 28 November resulted in several Coonamble streets being partially submerged.
Despite attempts from Coonamble Shire Council staff in the latter part of November to prepare for the excess water, a number of areas were inundated within the town.
On the corner of Castlereagh and Macquarie Streets a section of stormwater pipe failed and had to be excavated and reinstated ahead of the latest rain but then an outlet into the river also gave way over the weekend.
At the northern end of Zoccolli Street, close to the Sir Edward Hallstrom Bridge, another flap valve that releases stormwater into the river remained open after the river rose, causing flood water to flow back into the streets.
Water was pushed out of stormwater inlets along Yarran Street, pooling and causing concerns for houses around the intersection with Sydney Street.
A similar situation arose with the flap valve near the corner of Gordon Street and Coonamble Terrace in east Coonamble, completely flooding one side of Namoi Street from Macquarie Street to Tooloon Street.
A Rural Fire Service crew spent several hours pumping water away from homes.
Across the river, the stormwater outlet at the eastern end of Nebea Street that drains the north western section of the township also experienced problems and sandbagging was in order for nearby homes.
“Council checks and closes some stormwater outlets in preparation for a flood event to prevent flood water entering town,” said Executive Leader of Infrastructure, Daniel Noble.
“Some of these outlets are controlled by ‘gate valves’ but not all of Council’s stormwater outlets have gate valves, some rely on a non-return flap valve.”
“At times the non-return flap valves can get blocked open with debris, rubbish and grit which is all pretty common during a flood event. This prevents the valves from closing which means water can flow in both directions,” Mr Noble said.
The situation is not unique to Coonamble and is not a new issue.
A former council employee, who spent many years working on council’s stormwater, told the Coonamble Times that there are many factors that make it almost impossible to prepare and keep the town 100% water free.
“It’s always a case of balancing when to let the water go from the rain that usually comes with a flood and when to close the outlets,” he said. “And even then the flap valves can be opened by a tree branch floating by.”
“Some of it is our soils, and the way the river flows around corners and eddies against the banks where the valves are.”
“Once the river gets over 5 metres that’s when the trouble starts. It would have been a lot worse if it got over 5.3 metres.”
“It couldn’t be helped, you’re dealing with Mother Nature,” he said.
“You can’t predict where it’s going to go each time. You can prepare all you want but it will always break out somewhere else.”