Storm Water Runoff
Below is a capture from the final plans for the construction of the complex. The building permit issued 12th Nov 1998 See below
Included in that clip of the engineering plans is part of the material specifications relating to 225mm sewer pipe.
In capture below you will see the 225mm sewer pipe joining two Drain Grates ,Circled in yellow
There are two sets of these 1 between unit 6 and 7 the other between units 4 and 5.
225mm and 300 mm sewer pipe reference circled in orange
At retaining wall there is a 450x450 grate on top a drain pit circled in blue and a 600 x 600mm grate on top of a drain pit circled in purple in the lowest spot of common area between units 6 & 7
Similarly between units 4& 5
Below on next page is specifications of the pit at the retaining wall. This is pit that Peter found uncovered and with help of the two Mal’s cleared out.
When we cleared out the pit at the wall can see a circular inlet around 300mm in diameter full of mud.
Why they are not evident is not clear. The pit discovered at the wall shows they weren’t removed from the final plans. The common area was repaved. I have not found any documents existing for this.
Does the 225 and 300mm pipes actually exist .
We didn't know nor did plumbers whom Whittles engaged, know the pit was there, and indeed having charged us $1300 still did not discover it. Although they probably should have accessed these plans before quoting works for $13,000 to address fixing blocked drain.
So we need to be careful who we engage how we engage etc. Best way forward from that is for us to know exactly what situation is before seeking quotes for works etc.
So I am saying we need civil engineers advice on what is, and what should be done.
Does the 225 and 300mm pipes actually exist can they be made use of ( eg tapped into)
Can we make use if it. ??? If so there is a number options open.
But coming back to why are we looking at this. To avoid unit 4 and unit 6 from potential of having water unnecessarily flowing past their front door at a level that threatens to invade the unit.
If the grates and pipes did not exist water would drain the way it does now and has done for a number of years out over the retaining wall due to slope and elevation of land. We can help facilitate this further with a couple of measures at no risk or cost , Eg for  remove one brick at top of retaining wall to allow quicker release of water reaching the wall. Both at point between unit 6& 7 and between Units 4 & 5.
Unit 6 water intrusion under front door.
( by the way this has happened twice but not with serious consequence yet)
Unit 6 water collects in carport . There is a number of reason for this that I am aware of. But bottom line is you want to ultimately avoid risk of water flowing in under the front door.
Noting it comes very very close to doing that each time we get a heavy down pour, I am talking 2-3mm here.
This can be avoided easily by diverting water around door entrance (as I have currently and temporarily done with a brick) A 50mm “D” shaped door step with lip on upper side , in front of door diverting water around and Ito the drain. Would work.
A small 3 meter section of guttering will also reduce significantly the amount of water that accumulates at the wall near front door.
Let me explain here. Its two story and upper roof spills on to carport roof.
Now when you look at carport roof, from front, in the rain as Stan and I did you tend to think that whats coming off the carport roof is not contributing that much to the carport area.
However , that because the carport roof has diagonal raised hip. And all the rain caught on upper roof falls on the inside of the diagonal hip causing all the upper roof water to be dumped 2 meters away from front door. It has nowhere else to go but towards the front door. And since the unground drain catchment is half a meter in front of the door most of the water off roof flows along the wall and behind the draining passes a couple of mm below front door entrance.
A 2 meter piece of guttering and downpipe, and a raised door step would negate water intrusion under rom door due to storm run off. Estimated cost less than $900
Unit 6 Carport catchment
Even if pit drains in common area as per plans existed they would not work due to to landscaping of the area when pavers were replaced.
Re-landscaping the area in front of unit 6 carport to divert water towards the area where the original drain pit should have been would solve all unit 6 carport water catchment problems.
I believe that this can still be done at fraction of cost of some of other proposals talked about.
Unit 4 Carport River passed front door
Between Unit 4 and 5 is different story its not so straight forward as the landscaping when current pavers were put in leaves whole front area of Unit 4 unit below ground level in a sense.
Here a I believe a bigger “U ” drain needs to be installed.
But my beliefs above are only based on general sense of knowledge. It needs an expert to have a look. And gain point out not someone who has been asked to quote on how to fix it. As they view the whole project from point of view making the job easy but profitable.
We need to commission advice from perhaps a civil engineer.
With a brief to :
<1>access the drainage
<2>provide list of possible solutions with at least 3 being:
(a) low cost short to medium term solution
(b) low cost long term solution.
(c) long term recommended solution