Browse Forums General Discussion Re: Pumping stormwater to street -question?? 21Sep 20, 2011 9:50 am I could do a sketch but our scanner isn't working.... I can try and give measurements and maybe you could get an idea from that?? Will submit later (If it helps, if not, don't worry, but I can't scan an image). HHCIB Re: Pumping stormwater to street -question?? 22Sep 20, 2011 10:48 am Hey Stewie, In regards to the sketch, I'm shocking at drawing. I know my land has a fall of over a metre from my front left corner to my back right corner which is where the Council (Mind you I am in SA) is telling me my easement starts from. As far as I knew before I met with the local Council a week or so ago, this easement was only for the "lay of the land" and rains which pelted on the ground as I've requested my builder to have the water from my roof, gutters etc to be directed to the front of the house still with the height of them being well above council footpaths and roadways. BB Barossa Bubbles Building own design Fairmont Homes viewtopic.php?f=31&t=51265&hilit=Barossa+Bubbles Roof on-bricks next Re: Pumping stormwater to street -question?? 23Oct 02, 2011 9:32 pm OK, just revisiting this thread with a bit of an update... So after going around and around in circles (a few more times) trying to figure out what to do for our stormwater drainage, we called a plumber who lives just around the corner to come and give his 2c worth. He recommended that we try digging some holes in the backyard and filling it with scoria and creating pretty much a soak pit scenario. As he said, worth a shot because it won't cost much and it might just work (and, he didn't think - going by his eye - that the fall of the land would be in our favour to get the water to the street without a pump). So today, DP dug the pipe trench about 7m out into the back yard, then he started digging a massive hole - only to realise that we hit a bit of clay soil and also must hit the water level because water started seeping in. So we started to get a bit concerned that it might not work. Ironically, after not having much heavy rain at all over winter, here in Melbourne, we had quite a bit of rain end of last week so under our house ended up flooded again (just as we thought it was getting to the point of drying out ). So after concluding that the soak pit might not be the way to go, DP dug another trench from under the house to the big hole that he had dug to try and let some of the water escape out from under the house - and the water that poured out from under our house - it was like we'd opened up a dam - you could hear it gushing out from inside . It filled up the large hole in no time, so he dug another trench to the very back fence and out underneath (we back on to a school and our back fence backs on to a bit of a dead zone behind the school shed). So, now we have quite a few trenches and a large hole in our backyard absolutely filled with water which will take forever to dry out (and that's hoping we don't get any more rain in the mean time). But I'd rather it be in the holes and trenches than sitting under our house. DP is feeling totally defeated today - poor guy dug enough trenches for WW1 and our backyard does look like a bit of a war zone. He reckons he is going to tackle the trench for the front tomorrow and get it over and done with. So.... we are now back to the plan of piping out to the street. But... we aren't going to used a pumped system, we are going to use the charged system and do the best we can to minimise the likelihood of mozzie infestations (yes, some kind of closure, or nets over the drain pipes or flushing out the pipes regularly, whatever). Stewie D, like I said, scanner not working, but, if you're still interested/able to input, rough measurements are - gutter to ground approx 3m (I just did a quick measure) and front of house gutter to front curb approx 9m (maybe 10). Add another approx. 14m to back of house. Literally - How Hard Can it Be (where's the 'faint' icon when you need it ). HHCIB Re: Pumping stormwater to street -question?? 24Oct 11, 2011 1:39 pm We have the same problem. We are below street level (not by much) and the gradient is just toward the back.. I argued with our builder and the council (we couldnt finalise plans without the right system in place) and we were told really the only way we could do it was with a 'sealed' system (sounds the same as the flooded/charged system) to help drain all the roof water but we ALSO have to have a sump pump in the back yard.. Unless you have an extensive power outage and signifcant rain (possible but probably not too regular) it will usually be ok.. We have medium soil so we would need 2 massive soakage wells so it wasnt really an option in the end.. I didnt want my backyard to be all concrete from well covers.. LOL Good luck. It wasnt easy and in the end we are doing after handover as our builder wanted to charge 12k and we found someone for 5k without even looking very hard!! Building in Adelaide, SA Slab poured 08/09/2011 Handover 18/01/2012! WORLD CONCEPT HOMES Our build thread: viewtopic.php?f=31&t=44725 Re: Pumping stormwater to street -question?? 25Oct 11, 2011 6:12 pm Thanks for that Ashkate - and also everyone else who contributed and offered to help out via some guidance. We have decided to just 'go with the flow' (literally speaking) and push the water out to the street gutter via a charged system. We will not be using a pump (at this stage) and we have not involved the council (tsk tsk). It will mean some water sitting in the pipes but we will do our best to minimise any repercussions of this (ie, try and put in an inspection point so that we can clean it out as often as we are able - and perhaps put some fine mesh over the downpipe entrance in the roof gutters to avoid mosquitos flying in etc). It is all just about done - sans a few minor bits and pieces (like cutting the concrete kerb/gutter - but we enquired about hiring the concrete saw and it is going to cost $180 for half a day - and given we only need it for about 30mins it is just a bit hard to swallow so we are working up to forking out for that). Apart from that, hopefully it will be one major thing we can remove off our plate and fingers crossed DP's plumbing skills (or lack thereof) pays off when needed. HHCIB Re: Pumping stormwater to street -question?? 26Oct 12, 2011 11:36 am Thats great if you can do it that way!! Our sump pump is required purely from ground water as our backyard wont drain naturally, even having the roof water re-directed! Good luck!! Building in Adelaide, SA Slab poured 08/09/2011 Handover 18/01/2012! WORLD CONCEPT HOMES Our build thread: viewtopic.php?f=31&t=44725 Re: Pumping stormwater to street -question?? 27Oct 12, 2011 8:48 pm Thanks Ashkate. As I had said in the beginning, we went around and around in circles on this one and tried to explore all options. This option seems to be the easiest and cheapest - and fingers crossed it is effective. Hopefully it will all be totally finished this weekend and we can forget about it for a while... it's been on our minds and our 'plate' for the last 12 months so will be a relief to be able to move on to other exciting things that we have been delaying doing in the front and back yard until this was sorted. HHCIB Re: Pumping stormwater to street -question?? 28Oct 12, 2011 8:55 pm I would have thought that the council would want to see your final stormwater solution. Here in Warringah Council , they are very strict about what you do with your roof water and only look at absorption trenches etc as the last option. Not for existing dwellings but certainly with new houses or major renos. Stewie Re: Pumping stormwater to street -question?? 29Oct 13, 2011 7:29 am Hi StewieD Council never said they need to approve or check any final work. When I spoke to them, they were suggesting soak pits IF the soil was adequate and gave me the sizes I would need for my roof etc etc. Or they said we could 'pump' to the street. But they never said they come and check etc etc. Apart from interferring with council land and giving me the guidelines of what they do/don't allow (for eg, don't allow charged systems) they did not seem interested in being involved AT ALL. Fingers crossed it stays that way. HHCIB Re: Pumping stormwater to street -question?? 30Jun 08, 2012 11:07 pm Hi All, Apologies for bring back an older thread. I am having a similar dilemma with how to handle storm water drainage as my block slopes towards the back (about 90cm). I am in the middle of trying to subdivide and build a house at the back of the block. The council have "approved" but with the condition that there is a "drainage scheme" which is to be approved by the Responsible Authority (I'm not sure who this is but have been told by the designer that this is usually the building surveyor?!). After reading this thread, it seems that the solution is most likely to be a charged system as well. I have included a picture of the design so that I could get some opinion on the feasibility of using a charged system (otherwise, I may have to install pump(s) or some other complicated and expensive solution which was to have a private drainage at the back of the house which runs for over 100 metres and probably require easement on neighbouring properties). http://i1154.photobucket.com/albums/p531/buildnewbie/Housedrainage.jpg The other issue that I have is that I apparently have to connect to the council's pit which is on the other side of the road. To do this I have to "thrust bore" using 300mm pipe to connect to it which sounds like quite a costly exercise...Has any one had a similar experience? FYI, the property is in Oakleigh South which is looked after by the Monash council. Re: Pumping stormwater to street -question?? 31Jun 09, 2012 12:01 pm Naturally it varies from State to State but I have a friend whose house is about 2+ metres below the road. She has a concrete sump about a metre square and 1.5M deep that all her stormwater discharges into. Within the sump is a submersible float pump that switches on automatically as the sump water level rises and pumps the stormwater to the street via a 40mm pipe. Charged or wet systems are OK in some instances but you are relying on the water flowing down the downpipes to displace water and 'push' it through the system. In a downpour I doubt this would happen sufficiently quick enough to prevent roof-gutters flooding Arfur Re: Pumping stormwater to street -question?? 32Jun 10, 2012 3:28 pm Have you got the survey plan showing contours. I think there may be a way to have your stormwater drain to the street without pumps or charged system. The ore info the better. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Pumping stormwater to street -question?? 33Jun 11, 2012 8:58 pm Uncle Arfur, I'm not sure what the council will accept. I might need a pump system as well. As much as I want it to be cost effective to build I certainly don't want to have trouble later on. Casa2, I don't have the contour survey with me. But it slopes pretty much the same from the existing unit (look at the west view from the picture in my previous post). Maybe a slight slope down from west to east. on the approval letter from the council, it is stated that we have to connect to one of the pits Re: Pumping stormwater to street -question?? 34Jun 11, 2012 9:03 pm Sorry accidentally pressed reply. Connecting to either of the three pits will be very expensive. do you think we can request to get the storm water to flow to the street? Re: Pumping stormwater to street -question?? 35Jun 12, 2012 8:16 pm Having trouble imagining the contours. For instance, I assume the 400 HIGH SLEEPER WALL is such that there is a drop on your side of the boundary. If you can get all your gutters to drain to the left side of your house (side closest to the garage) then you can go from the house to the street. You do not need to travel perpendicular to the street and can angle the drainage pipe so that it goes at an angle and therefor has a fall in it. How does that sound? Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Pumping stormwater to street -question?? 36Jun 12, 2012 10:37 pm It pretty much slopes down gradually from the existing house and levels off about the last 5-6 metres once you get close to the back fence. Not sure about the drop on my side of the boundary actually. I was under the impression that the house will start where the garage door is and maintains the level from there which is why I will need the 400 high sleeper. I was thinking that the gutters will have to drain to the left boundary. For the pipes to go from the house to the street, wouldnt I have some pipe visible near the fence that runs along the left boundary fence? At least for the first 10m or so. Thanks for your input. Really appreciate all the advice. Re: Pumping stormwater to street -question?? 37Jul 13, 2012 9:09 am Here's one we had to do recently. Neither of the downside neighbours would allow an easement across the back of their properties so my client could run a stormwater pipe to the council gutter so we had to come up with an alternative solution. In this case a charged system. I thought it may be helpful for those that need to do something similar. Stewie Re: Pumping stormwater to street -question?? 38Mar 26, 2013 2:33 pm Sorry to bring up an old post, but this is the EXACT issue we are having right now. We have a 600mm slope on our property, the back being higher than the front. We are located in Whitehorse council (Vic), he council have suggested that we run an easement in the neighbour's property, this shouldn't be an issue as we are a subdivided block and she agreed to it on when the subdivision went thru. However this does sounds extremely costly, as her block is quite long. We are building double story and being that our slope is quite small we will definitely be above gutter level, even on the ground floor. So I am thinking that a charged system may be a cheaper and easier solution. Given that our block is somewhat flat (small slope) is this likely to work? And has anyone had any dealings with Whitehorse council? Re: Pumping stormwater to street -question?? 39Mar 26, 2013 7:50 pm You should talk to the council first to ascertain their guidelines and discuss preferences. It is best if you combine charged drainage with a detention tank that doubles as a rainwater tank. You need to take the roof plan area and multiply it by 2.2 to give you the litres drained per minute during a Melbourne 1:20 Average Recurrence Interval (130 mm/hr). This is the maximum drainage your eaves gutters are required to be designed for to be compliant. This figure will give you an idea as to the required tank size. I can't speak for Whitehorse council but many councils generally prefer detention tank systems as they limit the volume of water leaving the property that would otherwise impact on the downstream drainage capacity during a major storm. This is managed by the detention tank having a small overflow pipe fitted half way up the tank. For example, a 10,000 litre tank would typically have a 50mm overflow pipe fitted at the 5,000 litre mark. The overflow drainage rate plus the tank's mitigation is factored to the roof area drainage during the area's 1:20 ARI. If you opt for a charged system fed directly to the street, you would need to drain to a 100mm DWV pipe and design for a 1:100 ARI. If your roof area is lets say 200 square metres, you should factor a required drainage of about 650 litres per minute. If you had just a 1 metre head and the wet run was 70 metres, the 100mm DWV pipe will have a flow capacity of about 640 litres per minute. During a 1:20 ARI, the actual (rounded) roof drainage for our example would be factored as 200 sq m x 2.2 mm/min = 440 lpm. Over the same distance with a 1 m head, a charged 50mm DWV pipe will flow at about 95 litres per minute. During a 1:20 ARI, the 5,000 litre mitigation compartment being supplied by our example 200 sq m roof, a 1 metre head and 50mm overflow with a 70 m run would take nearly 15 minutes to fill. Note that this is approximate as the head varies as the tank fills. The top of your bottom storage compartment would also be above the roadside discharge level and this contributes to head pressure in a flooded vertical pipe. More head pressure = higher flow rates. Note; the above is an example only but head would not be an issue for you as the block slopes to the front. Reading through this thread, there have been comments made about charged pipes holding water but they also retain sediment when there is an upslope. Charged pipes should be fitted with a flush valve at their lowest point and this is easy to do. Problem solved. There has also been mentions of pumps on this thread. There are regulations that cover this scenario and they are found in AS/NZS 3500.3:2003 Section 9. As rainfall is variable, there has to be two pumps. This is because if there was one big pump and the rainfall was light, the pump would frequently cycle and this is a real quick way to destroy a pump. If there was just one small pump, it would not be able to handle a major storm event. The pumps have to be set up so that they alternate at start up and the system designed so that the number of start ups per hour is limited. There are other regulations as well that I won't go into here. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Hi all. I'm thinking of installing an electric gate in front of this street front villa (link below). The gate would be between the bush on the left and the letter box on… 0 2778 Thanks! I'm spoke to the builder I'm not sure if this is all true but basically went along the lines of they considered all options and if I was to compact and fill it… 2 7302 Plumbers 'can be' plumbers, made all the worse by self certification which the building surveyor invariably accepts as proof of compliance! The good thing is that you know know. 3 4859 |