Who you gonna call? Dam busters!

One morning in early March 2011, residents of Ryan Court, Drysdale found contractors digging a large hole at the bottom of their sloping road, immediately outside the last house in the street. They were told that it was to be a 'Bio-retention Basin', which was intended to filter impurities from the storm water running down their street.

This was the first that the residents had heard of this decision. As the residents watched this two-foot deep 'Basin' (effectively, a storm water dam) fill with rainwater that failed to drain away as promised, they tried to discover more about it from the City of Greater Geelong. Council officers gave them the runaround and said that the council had sent a letter to all the residents in 2010 informing them of the decision to create the dam. No-one received such a letter.

The residents asked DCSCA for assistance. as a result, a meeting was held on site between Cr. Rod Macdonald, Mr. David Hannah (CoGG's Manager, Engineering Services), Ryan Court residents and DCSCA's Doug Carson and Patrick Hughes. At the meeting, Mr. Hannah said that the pipe feeding the dam would be turned off within the week, allowing council engineers to examine it.

Subsequent to that meeting, DCSCA wrote to David Hannah on 22 July 2011(copies to Cr. Rod Macdonald and Ryan Court residents), summarising what had been discussed. The following is an extract of that letter:

1. Role of the dam
You said that the dam has been built in accordance with CoGG's requirement that the rainwater run-off from the new estate at the top of the road should be no greater after the development than it was before. This requirement is imposed on every proposed development. CoGG officers assess the plans for each proposed development to ensure that it will not increase rainwater run off and, if the plans show that it won't, CoGG approves the development. CoGG doesn't examine each completed development to ensure that the run off is, indeed, no more than it was previously. Instead, it relies on its engineers' professional assessment of the plans.

Our response.
As you explained this policy, it became clear that the construction of the dam in Ryan Court was part of the proposal to build the new housing estate. CoGG gave planning approval for this estate some time ago, so it is hard to understand why the residents of Ryan Court were given no opportunity to comment on the dam until the morning that contractors arrived to construct it.

Further, the residents have noticed an increase in the rainwater run-off in their street since the estate was built and this, together with the fact that CoGG has built the dam to 'process' that run-off indicates that the run off from the estate has increased and is being off-loaded to Ryan Court, rather than being dealt with in the estate itself. The residents of Ryan Court are suffering the effects of the new, CoGG-approved housing estate, while enjoying no material or financial benefit from it. We would like to see the plans for the new estate that CoGG engineers approved, to see whether they include the dam in Ryan Court.

2. Purpose of the dam
You said that the purpose of the dam is to improve the quality of the water running off the new estate at the top of the road by filtering out 'phosphates' and 'nitrogen'; and that the filters in dams like this are cleaned-out every eight years (approximately). However, you were unable to say by how much the dam will improve the quality of the water issuing from it.

Further, residents said that there have been oil slicks and detergent foam on the surface of the water in the dam (they have photographs of this) and you were unable to state whether the dam's filtering system can deal with such pollutants. Nor could you say whether such pollutants affect the ability of the filtering system to deal effectively with the 'phosphates' and 'nitrogen' it is designed to neutralise. Finally, the residents pointed out that the water going through the dam into the creek at the bottom of Ryan Court is just a fraction of the total amount of water that flows through the creek, which is fed by the run-off from Murradoc Hill. Also, as you said, the water going through the dam is just a fraction of the total water flow down Ryan Court, most of which flows through a separate drain pipe.

It is reasonable to ask whether an unknown measure of improvement to the quality of an unknown (small) fraction of the total flow of water justifies the distress and disruption that has been caused to the local residents.


3. Safety and health issues with the dam
You said that there is no requirement to erect fencing around the dam because the angle of its banks conforms to the relevant standard.

Our response.
As you heard, parents are worried that the lack of any fencing around the dam means that children may slip on the banks, injure themselves or even drown. (Children in the local area have been used to playing in the area now occupied by the dam, because it used to be a little park, including trees planted by CoGG.) As you also heard, the dam disrupts an informal short cut across the creek that has traditionally been used by local people - especially local young people. The lack of any fencing means that people using this short cut - especially in poor light - may also slip on the banks, injure themselves or even drown.
Finally, while this wasn't discussed at the meeting, you will be aware that areas of stagnant water - such as this dam - can harbour vectors of various diseases, yet CoGG appears to have taken no measures to prevent this happening.

In a separate development, Ryan Court residents and Doug Carson each received a phone call from Cr. Macdonald saying that the dam would be filled-in and that the council would send a letter to that effect to residents by the end of the week! On Thursday 28 July, Ryan Court residents received a phone call saying that the letter had been posted and that they should receive it either the next day or the following Monday (1 August).

Watch this space!