Browse Forums Landscape & Garden Design Re: Rain Garden Cost- HELP!! 2Apr 28, 2017 4:49 pm Nev _________________ Blog | ( will start once received tender ) H1 thread | https://forum.homeone.com.au/viewtopic.php?f=31&t=77665 Re: Rain Garden Cost- HELP!! 3Apr 30, 2017 10:25 am 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rain Garden Cost- HELP!! 5Apr 30, 2017 11:37 am It depends on what the council will accept, a retention and detention system is best but that depends on the site gradient (hydraulic calculations) and then the aesthetics. Given the fall of your land, you would have a retention component anyway. Many councils wisely don't allow pumped systems for the reason I posted earlier. A single pump also needs its flow capacity to match the council's Permissible Site Discharge (PSD) but 95% of Melbourne's 'rain' is drizzle or light showers, this most often causes a large pump to cycle which is bad news (very damaging) and the reason why dual pumps operating in tandem should be used. I would avoid a pumped 'solution' at all costs (please excuse the pun). What is the planned landscaping? Could you incorporate something like thin tanks as a multi purpose solution? http://www.teampoly.com.au/downloads/Ra ... -Flyer.pdf http://www.tightspottanks.com.au/thinta ... ater-tank/ I would seek advice from the council on their PSD requirement and their acceptable solutions as a first step but you need to talk to someone who is knowledgeable in the art and that can be a frustration when dealing with councils. Try to get the message across that you have no confidence in using a pumped system and explain why. If the levels and hydraulics are ok for a detention system, then that is the lower cost solution. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rain Garden Cost- HELP!! 6Apr 30, 2017 11:52 am ayaman In a nutshell the tank, .......................... is basically too low which is why we require pump system to push all the water out to the LPOD. Just saw the edit. Can you post the height difference between the bottom of the gutter and the LPOD? 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rain Garden Cost- HELP!! 8Apr 30, 2017 1:42 pm Just measure it, use mortar lines as the line of sight and ask someone to hold a stick with some graduated marks on it at the kerb. The builder has said that the tank is too low but maybe you just need a higher tank. There may be options that don't involve a big bulky tank if that is the case. The link below is to AS/NZS 3500.3. It is the 2003 version which was updated in 2015 but the information relative to your situation is still accurate. Pumped systems are in section 9. https://law.resource.org/pub/nz/ibr/as- ... 3.2003.pdf 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rain Garden Cost- HELP!! 9May 01, 2017 12:11 pm I have seen on the plans that you sent by PM that you will have two pumps as per Section 9 of AS/NZS 3500.3. Section 9 also has other requirements that includes a warning siren should the pumps fail as also shown on the plans but electrical pumps won't start during a power failure and at some time, you WILL have a power failure during a major storm event. It should be noted that AS/NZS 3500.3.9.4 states: "The pump controls shall be set up to enable alternate pump operation at each start." This is to avoid cycling which is damaging to a pump's motor. I would query whether the plans satisfy this. The plan's design also shows that you will have two big pumps with 5 lps each, this is 600 lpm discharging to the kerb during a heavy rain event!!! There should preferably be a limited detention discharge but as surface drainage also needs to be factored, the system would be following the Moonee Valley Council edict but surely the council would prefer a more suitable alternative or do they want a tourist attraction? If the total roof area drained included onsite detention with limited discharge, then smaller pumps could be used subject to council approval. Your 5,000 litre water tank is a retention tank that will receive a diversion of approximately 400 litres per minute from the 183.29 sq m of harvested roof during your area's 1:20 Average Recurrence Interval (ARI) but this will way exceed the tank's 100mm overflow pipe's discharge capacity. Melbourne's 1:20 ARI is 130 mm/hr, based on a 5 minute average rain intensity of 2.166 mm/min. 183.29 x 2.166 = 397 lpm. A tank's horizontal discharge capacity is calculated by the depth of water above the overflow pipe's invert (bottom of the pipe) using Torricelli's theorem but water tank overflows are also meshed and the mesh typically has an open area of about 55% which presents a flow restriction. If you look at Figure 8.2 in the link below, you will see that an unmeshed 100mm overflow pipe will flow at about 300 litres per minute with approximately 110mm of water above the invert but your overflow will be meshed unless they use an external flap valve. Using an internal bell mouth orifice would be my preferred alternative to increase the overflow rate. https://ia801901.us.archive.org/20/item ... 1.2003.pdf A charged pipe to the water tank is necessary when the tank is remote to the downpipes. To divert water into the tank, the pipes run underground and this requires head pressure to get water into the tank. The head is provided by the downpipes. The reason I asked for site levels was to see whether a suitable retention/detention system could also provide the head to divert stormwater directly to the kerb but as there seems to be no PSD, then the downpipes could do this if the levels were favourable. If so, smaller pumps could then be used for the surface drainage. Thinking outside of the square, I think that an alternative solution could be provided at a lesser cost if my own belief was followed in that every new house site should be required to provide groundwater recharge for environmental reasons. If you were able to have a bore sunk that was also used for onsite discharge, it would be a win-win situation. I don't know what the cost would be but it might be worth passing the idea by the council after assessing the design feasibility, getting some quotes and determining the depth of the water table as doing this would eliminate the need for the very expensive pumping system and maybe even the rain garden as well as eliminating additional stress on the stormwater system...which should please the council. There is information available on the internet about ground water in all areas of Victoria and falling groundwater levels is an environmental concern in numerous areas. You are paying too much for your water tank installation, I can advise on how to save a lot of money if it isn't too late to do so. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rain Garden Cost- HELP!! 10May 02, 2017 8:01 am No it isn't too late to make changes to the water tank. Everything is on hold at the moment while we figure out this water tank/ pump drainage issue. We don't have the money to spend on it so we are at a standstill while the builder investigates other options. Hi, does anyone have any experience with using Trex rain escape or EPDM rubber to waterproof a deck so you have dry space underneath. Popular in the US and realize that… 0 3417 Yes you are correct, unless there are outside works which form part of the contract such as landscaping or driveways, and importantly, the work delayed is on the critical… 1 3497 Hi When it rains in a particular direction water comes through the security door. It hits the main door and the bottom swells and jams. There is already a cover over the… 0 38425 |