3rd Jan 2006
To the CEO
Dear Russell
Happy New Year.
Hope you had a nice holiday. Could you please put this on the agenda for next Tuesdays General maybe it might be appropriate as Business from Minutes but I will as always take your advice.
All the Best
Ron Owen.
Business from Minutes of the13 12 05.
Page 41,
Late Item 4 Headed Gympie Securities Pty Ltd Storm Water Drainage.
From Leddy Sergiacomi and Associates Pty Ltd.
I believe that, within our duty as councillors that this letter from LSA should be answered and corrected to insure that no misconceptions from this letter be carried forward to cause further damage to the people or their homes in this development.
I would have preferred one of our staff engineers to make these corrections and points in a more concise and from a more informed educational background, but as this has not occurred this is the only recourse open to me so I intend to send this letter to LSA and ask for their comments if the council itself does not endorse and send this letter itself.
To Leddy Sergiacomi and Associates Pty Ltd.
Sunshine Coast Office
Level 1/25 Bulcock Street
PO Box 1256
Caloundra Qld 4551.
Attention Bruce Johnson
On receipt of your letter of the 9th December 2005 it was presented to me on the 13th December at the Council table. I have the following problems with your letter could you please correct me if I am wrong and supply the basis on which you have substantiated your views. I find your letter to have an overall shortage of substantiation within it.
1. Quotes from LSA Letter of the 9th September 05,
“the records available to date are of little relevance to this catchment”.
“(Toolara) recorded 100mm in the 2 hours period from 4.pm to 6.pm on 1st December 2005 Officail BOM daily rainfall data indicates 115.6 of rainfall fell in Gympie for the 24 hour period (9am to 9am)”.
If no records are available for this catchment, why did LSA say in their Consultants report dated 6th April ref 44U-035 page 3 2.1
“General
The catchment area to the overland flow paths examined has been determined from existing contour information, discussion with BJS, and from site inspection”.
then the report refers constantly RAFTS Model constructed by your company,
See Appendix A and B to this consultants report, Headed
RAFTS output current State of Development.
and RAFTS output- Ultimate Development. Some thirty pages are headed.
“Summary Of Catchment And Rainfall Data”.
We would be led to believe at first instance that these figures were real.
Are you admitting that this consultants report was incorrect and subsequently the KBR consultants report that Council paid $30,000 for are flawed? As KBR state honestly on page 4.
Paragraph 6,
“As there was no available flood discharge data in the study area the calibrations of the RAFTS XP model was carried out following regional techniques.
and in a letter under the heading of KBR to Mr Grayden Curry on the 6th July 2005, sub heading Gympie Securities Stage 6 and 7-Stormwater Drainage Response to LSA.
“For this review the RAFTS model setup for the development was provided by LSA. The reason of requesting the model was to review the model parameters used to estimate lower design flood peaks than KBR”.
It does not need much imagination why LSA would want to estimate lower flood peaks but as it has now been admitted that nearest information that was possible was from Toolara how can Council have any faith in any of the consultants reports which are based on rainfall from another place. How can you compile a 30 page report “Summary Of Catchment And Rainfall Data” from rainfall which does not apply to the site and obviously does not allow for Gympie’s highest rainfall of 336 mm in a 24 hour period and we have had problems occurring with as low as 50 mm per 24 hour period?
For example it does not need to a Hydraulics Engineers to work out that if Gympie can have by BOM records 336 mm of rain in a 24 hour period and LSA conclude or assume that 100mm fell between 4pm and 6pm on a day when we had 115.6 mm then on the simular assumed ratio (as those figures come from Toolara) we can assume that when this day re-occurs as weather often does then this catchment could easily have 300mm in 2hours or more. If the highest rainfall of Gympie is one day exceeded, as records for this area are just over 100years old, they can be exceeded on any day. The flood water they assess at 100 mm for 2 hours on 1st Dec 05 would be 300mm and instead of one metre of water in Castlereagh Court there will be 3 metres. If this water was allowed to spread out over open areas it would not be so bad but as the engineers in this development have ignored the conservative method of piping Storm water underground and instead have recommended and approved four flow paths through the streets, between houses which are homes, the consolidation of water from rooves, road gutters, the fall of land from the Industrial Estate to Marc Dower Park, the diversion of the natural creek to the flowpaths, the inadequacies many small 600mm pipes to an eventual single same sized pipe has increased the velocity of water, (as observed by the video). This has caused increases in the velocity of this Storm water which of course increases the force of water due to the weight and is only resisted by friction. This weight of water due to the reasons above causes the velocity to increase times by the increase in water in the system from above. So when a 3 metre wall of water hits Castlereagh Court and surges across the road way and hits the house on the corner next to the Marc Dower Park, the windows and brick veneer will not withstand the weight of water and would push the home into the river which will be in Marc Dower Park. You may say this will not happen but could these consultants KBR LSA BJS and the Council please guarantee this to the people of this development. Would you personally put your career, your home and your life into saying this will not happen due to your companies involvement in this development? You may think this questions is a little over the top but the people, our ratepayers, who on our advice and on the advice of your company are doing that by investing their fortunes and lives in those homes in Castlereagh Ct and Mc Fail St. Those people who live there have invested with Gympie Securities bought the land built their houses and trust the system is safe and trusted a council to make sure that it is. They have put their lives and fortunes on the line I am only asking for you to do the same.
Engineers design objects they effectively change the world. Civil engineers in this case have changed the natural Storm water flow. In my capacity as a Firearm designer and as an Engineer, I design firearms with a safety factor due to gas pressure risks in the vicinity of 10 to 1 that is 20 tonnes of Pressure in the chamber when tested should withstand 200 tons with a special overloaded test round. Engineers who build dams and buildings have safety factors, as it is not my field I do not know what they are, but, what I do know as I have seen it with my own eyes, there is no safety factor in this Gympie Securities development for Storm Water, completed or not, in fact, I an others believe that when it is completed the water will travel quicker and it will be more dangerous.
2.Quotes from LSA Letter of the 9th September 05.
“Generally the major flow paths from the upper catchment and into Mc Phail Street were consistent with the design intent, the grading of the Mc Phail/ Grosvenor Court intersection ensuring that all the overland flows upstream were directed to the Mc Phail Street corridor.”
In this sentence you are stating that in this area the system worked as designed. When in reality much more water was running into the retention basin than was going out this was evidenced by the retention Dam filling up and overflowed after 3.pm and it only stopped over flowing after 5pm when I first arrived it was still flowing over the wall by half an inch, the rain had stopped, I unpacked my camera and took photographs (see video) by that time the ground was still wet and the Dam was overflowing part of the wall. The rain had stopped and was draining from the underground pipe, the dam was still overfull to the brim.
What if a child had gone for a swim in the dam and been sucked to the bottom of the pipe? This retention basin acts like a whirl pool and has tremendous sucking power, it is another unsafe liability.
The excess water from this Dam overflow, followed the creek and some went overland towards Grosvenor Court. Where the original creek has been diverted the hole filled to the top, the 600 mm pipe that runs underneath the flow path, was submerged ten feet below the water level. The then uncompleted Flow path was only wire reinforcing and the concrete had not been poured so the overflowing water from this creek and the dam spread overland and carried down until it went over the wooden retaining wall Like a giant water fall 100 yards wide, I have photographic proof from later in the day when the rain had stopped the water was still going over this wooden wall in a waterfall 10 metres wide. Much of this water had flowed down Grovenor Court and then gone overland to go over this wooden wall. At the Intersection at the high end of Mc Phail and Grovernor Court, there was a massive pond or dam as the hollow in the ground of this pond covered the intersection and left a huge pond after the rain had finished. How can you say “consistent with the design intent”. All this fast moving water from this upper catchment on the Exhibition section went through the Church /Dekker Development either through the small almost insignificant pipe system or over the wooden retaining wall to then flow down the path way into Inverary Court, then through the next flow path to Castlereagh Court. Any person Child or Adult caught in these two flow paths may have been caught by the body catchers, Wire mesh at Castlereagh Court but if they were dead by the time they got there they could easily have been swept to the side or gone over the top along the road and into Marc Dower Park. If you question how I know please (watch video) and believe me, I was there as an observer I am a strong swimmer but I would rate my chances of surviving this velocity and weight of water, on that day at its peak as 50%. Yes Teenagers were playing in it at Marc Dower Park but it had been allowed by the park ground to spread out to some degree and at its peak no one was in the central flow area.
Water had run down Mc Phail Street carrying down tons of earth from the yet to be built on blocks at the upper end, the two section of unsealed road lost a lot of its fill, but most of the earth material that was left in the water system came from this upper catchment areas, as proof of this see photographs of silt on high end of Mc Phail St on video.
3.Quotes from LSA Letter of the 9th September 05.
“a large proportion of the upper catchment are (ie greater than 50%) was under construction for future development of the estate…….It is considered that the catchment was at its most vulnerable in terms of runoff with little grass cover and the entire length of upper Mc Phail Street was unsealed”.
Yes, we know that the area was saturated by the two earlier showers which had half filled the retention dam, the ground was wet, In Queensland we have wet periods which last three or four months. Surely, safety factor have to be designed into systems which allow for wet ground, surely everyone is aware that a housing development, with rooves, gutters, driveways, roads patios, concrete gardens all create more runoff than natural ground which is to be developed at some future time. If it has little grass cover this is inconsequential in comparison of when this development is supposed to be completed. The ratio of soakage of Storm Water into Natural Ground compared with Developed Housing is a figure that I do not have at my disposal but commonsense dictates that natural ground absorbs better than concrete and when this development is completed there will be very little natural ground left. So the conditions were not bad on the 1st of December they were the best it gets, this problem will only get worse until it is rectified. When all of this ground, on both sides of Furness Street. is developed all the Storm Water still has to drain through two pipes in Castlereagh Court.
4.Quotes from LSA Letter of the 9th September 05.
“Factors”
“In the upper areas no flow was entering the underground system as partly completed pavements were washed out subsequently all runoff was surface water”.
How could this be a factor? When the underground system was full to bursting point (and will be in any future event as both consultants reports KBR and LSA both agreed that the underground pipe system was inadequate for any storm water flood event) as the manhole covers blew off. The 65 kg cast iron covers which should be bolted in place with bolts over half and inch in diameter (see video as bolt heads are missing) the underground system that Council and Dekker development installed to take Gympie Security Storm water through the church ground, geysered and pushed the steel grates out of place. This was only a percentage of water that went past that point as the majority came overland from the wooden retaining wall. When the system is completed the only flow path not completed on the 1st of Dec 2005 will be finished so in future this water will come down that flow path at a much greater speed, then it came overland on this instance and in future all will end up at Castlereagh Court over a shorter space of time. The proposal and your companies initial consultant report agreeing to these over land flow paths instead of piping the storm water underground could in the future be a great embarrassment to your companies reputation.
5. Quotes from LSA Letter of the 9th September 05.
“The two failed pavements sections in Mc Phail Street upstream from the Mc Phail Street weir structure were under repair and subsequently were washed out. The above resulted in deposition of material through the drainage system.”
In every summer storm preceding this event, prior to 1st December 2005 earth from the development has broken through the inadequate silt catchers and ended up in Marc Dower Park and been blocking up the culverts on the College Rd side of Glastonbury Rd. Council has had to attend to the removal of this earth, I took photographs of tons of it prior to the event in Marc Dower Park. I believe the force of this storm event would have at least purged the soil trapped in the pipe system from previous failures of the development. The two sections of the Mc Phail St wash outs, were inconsequential in comparison with the earth from the higher end which is vacant loose land.
Are we really talking about a Weir structure to Mc Phail Street/Castlereagh Court or are we talking about canals or rivers, as this is a housing developments with peoples homes and children, and you have consulted on and been a part of designing which is a part of building a weir in these streets. Many cubic metres of water missed this weir entirely and began another river which put a foot of water through one house on Mc Phail Street and inches into a house on Castlereagh Court
Should we be calling them streets, courts, roads, or is your companies expertise in designing canals and rivers?
6. Quotes from LSA Letter of the 9th September 05.
“Flows from Decker’s land- the photographs reveal that there was abnormal surface flows from this development.”
The largest amount of water by far, was from over the wooden retaining wall from the Gympie Securities which entered the Church property and subsequently went over the Decker development from the church and went into properties in the rear of Mc Phail Street. Also is the writer ignoring the amount of pipes from Gympie Securities which meet at the retaining wall corner and then travel through the Council pipe to Deckers development and then enter the Gympie Security development at Inverary Court.
All of this water is from the Gympie Security development, and is their responsibility, why not admit this and address the problems from this point, as it is only when we can look and see the problems, can we have a hope of solving them.
7. Quotes from LSA Letter of the 9th September 05.
“The Incomplete state of the weir inlet -Inverary Court”
No matter how they shape the roadway, this entry point for the water at Inverary Court would not have made any difference. The pavement being the road bitumen is standing proud but the water came down it with gravity and did not have to go up it, it was not an obstruction, but two foot of water across the whole street and the nature strip, 20 metres wide is not going to all go down the 4.5 concrete path way or the 5 metere pathway reserve which was in place before your company designed and included in its plan in the Consultant report Figure 2 Job No 44 V-035 by RLB on the 5th April 2005. In this development like all others, where people invest their life saving into their homes this is a disaster which all involved have some responsibility. If by a miracle all the water had gone down the pathway it would then have overflowed and gone into more houses on either side of the flow way.
8. Quotes from LSA Letter of the 9th September 05.
“Portable Barriers… impeded flows and were responsible for turbulence and adverse flow conditions in the vicinity of the entrance to Castlereagh Street corridor”.
It is true that these plastic barriers did block a lot of water from entering Castlereagh Street they were caught at the Body Traps recommended by your company on the 6th April 2005 at the bottom of page 7 of your consultants report.
“We suggest that in the interest of pedestrian safety consideration may be given to the provision of a suitable fence or handrail being erected on the downstream side of the footpath in the proximity of the outlet headwall in the park”.
These fences trapped the large Plastic Barriers that had been washed down from Inverness Street and Mc Phail Street and while they created turbulence (as did the fence itself) they did a great job in slowing down the water entering Castlereagh Court , this kept the height of the water down which prevented the water flowing into other houses. As you see in the video once the Council workman removed one of the two plastic barriers, caught at the body traps, the water level went up in Castlereagh Court and began to enter the house opposite, the house next to Marc Dower Park. We cannot depend on the plastic barriers being there in future Storm events, to slow down the water.
9. Quotes from LSA Letter of the 9th September 05.
“In our view what now need to occur is to determine specific solutions for each of the properties inundated to prevent a recurrence of flooding”.
How can we trust any advice this company would offer us just on the premise of the above statement. If we followed this advice, and allowed the development to continue and only address these individual problems as the development continued towards the top of the hill near the industrial estate and around the higher ridges above Inverness Street and Furness Street the consolidation of water flows would increase and even if we put levee banks around each home, (as it has been admitted in both the KBR report and the LSA report) that the Storm drainage pipes are inadequate at the lower section of the development. Unless these are rectified with the correct sized pipes, as the development continues, if they make bigger pipes at the top end, it will not make any difference, all that extra water has to come through the lower section into Castlereagh Court and lower Mc Phail Street.
What comfort to the residents trying to sleep on a wet rainy night, is this proposal from LSA? This problem has to be rectified by using the correct sized underground storm water pipes. In any housing development the appropriate place for the Storm Water is under the ground in pipes and culverts not on the footpaths and around peoples homes. If you have any doubts that this catchment has undersized pipes look in the older part of Gympie, have a look at the size of the pipes that service similar sized catchments as this, look from Duke Street at the Culverts near the Karate Club on Iron street, have a look at the size of the pipes coming into the Mary river from the centre of town.
How can we trust your companies advice as they have been partly responsible for the design of it and have been paid by the developers. How can we trust your company to rectify the situation and not just follow the same weather beaten path of defending the past and blaming everyone else. How can we trust your company after reading this letter which does not even correctly acknowledge the cause in which you were more honest about in your Consultants report to BJS on the 6th April 2005, where you acknowledged that the pipe system is inadequate by stating on page 7.
“This footpath area (referring to Castlereagh Ct) and road sag will provide an area where pedestrians which may be in difficulty, could regain footing and avoid the possibility of being swept into the deeper drainage channel downstream.” “It is noted that the depth x velocity product is in excess of the QUDM limit, which indicates some hazard to pedestrians”.
Yours
Councillor Ron Owen JP (Qualified)
Quote
“The strength of a nation is derived from the integrity of its homes.”
