Browse Forums Landscape & Garden Design 1 Apr 04, 2013 10:46 am Hi Everyone, Firstly I want to say a huge Hi to everyone and thanks for their comments / posts in the Landscape & Design sub-forum! I've just spent the last 2 hours going through hundreds of posts and often saying, "Wow!!!!!!" "My Goodness..." "I didn't know that." "I wish I'd known that before hand" My partner, Lisa and I have a rather large block based here in Victoria (Bacchus Marsh). I've attached a couple of photos to show you our plans and goals. We're on 1,750 square metres with a sizeable back garden. From a sustainability perspective we've installed x2 22,500 water tanks with the storm water being diverted into a sump pit and then into the tanks. We've recently installed solar and enjoying the benefits of that! Our garden at the moment is an open canvas. We've cleared everything out and want it to be an oasis of peace, colours, birds etc.. Having done a little research (no where near enough) we were just about to install some sub-irrigation with the lofty goal of having a fully automated watering system in place utilising the water from the tanks etc. With created some basic zones we know where we want some plants. Now having read Fu Manchu's threads about soil preparation my plans have come to a CRASHING stop!!!! My soil is crap.... no doubt about it... A mixture of fill (which I've got rid of mostly) and clay... As in, really hard clay and it simply keeps going down!!! Thank goodness I've read Fu's preps.. His words make sense... Here I am thinking that I can merely put down the sub irrigation, bring in potentially, $3,000 of top soil, lay some turf or grow via seed and hope for the best... I don't think so.... Lisa and I have invested a fair bit of money so far in setting up the infrastructure, our tank. The ring-main so we can zone our garden effectively, water it effectively and thinking about future water issues. ie. drought! That was definitely a reason for thinking about the sub-irrigation. We were about to purchase the Kisss products but reading the recommendations the netafim products are more recommended. Note, from a herbecide perspective the sub-irrigation will not be hooked up to mains water so not back flow issues there. So much information is on this website that I'm just starting to fathom. Unfortunately there is so much mis-information or recommendations on the web about products/techniques etc. I simply want a garden that will be as maintenance free as possible but mind you I don't mind spending say $20K to $50K over the next 5 years making it our oasis. Our house were rapt with (it's 10 years old and nothing to do on it). We love where we live! Thanks for reading. Here's some photos to show you some context! Me Lisa Garden Plan - Google Sketch Up is my friend! Garden Zones View into Backgarden from house Upper Level - Stones Cleared Trenching Kind Regards. Benjamin. ps. Let the Journey begin! Re: Bennie and Lisa's Landscape Project - Let the fun begin 2Apr 04, 2013 2:40 pm Wow, that is a clean slate! well almost, you have got a few of the structural elements underway I see. Well done. Your google sketchup plan looks like a good basic starting point. Good on you for getting in there and having a go yourselves! There are plenty of helpful folk on the forum so feel free to ask any specific questions you may have. All the best. Dave Re: Bennie and Lisa's Landscape Project - Let the fun begin 3Apr 05, 2013 9:33 am Online Gardener AU Wow, that is a clean slate! well almost, you have got a few of the structural elements underway I see. Well done. Your google sketchup plan looks like a good basic starting point. Good on you for getting in there and having a go yourselves! There are plenty of helpful folk on the forum so feel free to ask any specific questions you may have. All the best. Dave Hi Dave, Thanks for saying Hi! Appreciate it! Yes, a clean slate we've definitely got there. I'm looking at following Fu's soil prep. Google Sketchup is fantastic. Very easy to use... Lisa and I are right at the start of plant selections, what theme, style, features etc... We went to the Melbourne Flower and Garden show 2 weekends ago and got some ideas. However many of them are very expensive Lisa and I enjoy the garden and are willing to give it a go. Why pay someone thousands of dollars when you can do it yourself at a third of the price! Resources like this forum and others help enormously. I'm still tempted to install sub irrigation though, particularly in thinking about the future when we hit water restrictions again. The x2 22,500 litre tanks will help but when it doesn't rain for 6 - 8 weeks like it did this summer the water will deplete fairly quickly. Righteo time to get stuck back into some work! Cheers Bennie Re: Bennie and Lisa's Landscape Project - Let the fun begin 4Apr 05, 2013 1:21 pm Hi Benjamin & Lisa. Firstly, is the plant growing next to the house (near Lisa in the photo) a Radermachera sinica? If it is, then I have to warn you that these grow very large outdoors and the spot chosen is not appropiate. My main concern however is with your rainwater harvesting system and it sounds like the tanks are already plumbed. Are they and if so, what is the roof plan area harvested, what pump(s) do you have and how big is the pit? 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: Bennie and Lisa's Landscape Project - Let the fun begin 5Apr 05, 2013 2:11 pm SaveH2O Hi Benjamin & Lisa. Firstly, is the plant growing next to the house (near Lisa in the photo) a Radermachera sinica? If it is, then I have to warn you that these grow very large outdoors and the spot chosen is not appropiate. My main concern however is with your rainwater harvesting system and it sounds like the tanks are already plumbed. Are they and if so, what is the roof plan area harvested, what pump(s) do you have and how big is the pit? Hi SaveH20 Nice to meet you The plant you mentioned is being removed. Thanks for the warning, the previous owners had put this in. Oh my... I just did a quick google search on that plant... Wow. It can grow up to 30metres tall with a 1 metre trunk! No wonder you warned me against it... Ouch!!!! Let me fill you in about the rain harvesting system we've got here at home. We have x2 22,500 litre tanks. The storm water that would normally go out to Western Water's main drain is diverted into a sump pit. Roof Area (including the barn) is 344 square metres. I've gone outside and taken some photos to show you the layout. Tank / Sump Pit Location Sump and Pump The storm water is diverted into the sump (600mm Everhard Poly Sump with 200mm extension. Pump is a Davey Sump D40VA http://www.davey.com.au/site/DefaultSite/filesystem/documents/datasheets/DPM124-3%20D15VA_25VA_40VA.pdf 0.4kW. The head is about 3 metres giving approx. 200 litres of pumping ability a minute. As can be seen in the Tank / Sump pit location photo the tanks are temporarily hooked up together but not going anywhere *yet*. The idea is to ring-main the property over the next few weeks with 40mm Poly all the way around the property with a number of zones etc... Solenoids etc... Looking at the Hunter control unit etc.... Can you see anything that is glaring wrong with the install above? I've gone down and checked the sump when it was raining quite heavily the other day and the pump was churning along fine faster than the rainwater flow. Note, there will be an additional water collection point (in my first post see the trench that I'm digging?) that will be another 35 sq metres of water collection going into one of the existing storm water pipes. We haven't decided on a main pump for the ring-main yet... Most likely another Davey.. Not sure. To give you guys/girls an idea of what we're up against I took some shots of the soil: Soil Condition 1 Soil Condition 2 Soil Condition 3 As can be seen we're looking at compacted, abused soil in which the only thing that grows is weeds I've spent my lunch time today going over Fu's posts and I have to say I'm in information overload at the moment and it's hard to know where to start. We decided on the tanks first as we don't want to solely rely on mains water, nor do I think it's an environmentally thing to do. Doing my calculations on 380sq meters of roof space. Melbourne Average rainfall (being conservative) 600mm, multiple that by 0.9 means that the house can potentially collect : 205,000 litres of water. Overall, I'm starting to fill a little out of my depth but trying hard none the less. Even say with the clear out of the stones, and I'm now pointing in the extra stormwater pipe. I've suddenly realised that If I'm going to follow Fu's plan it means I should be getting the rotary hoe out first and churning the whole lot up with the relevant organic matter etc..... and THEN put the storm water pipe in. The more I read about soil preparation the more I understand just how important it is.. I look at the photos I took of my soil and think, geezzzz. how the hell is anything good going to grow in that? It looks sterile and probably is. I want my plants to be healthy not stunted because they'res no nutrients.. Thanks everyone and apologies for such a long post! Cheers. Bennie Re: Bennie and Lisa's Landscape Project - Let the fun begin 6Apr 05, 2013 3:36 pm Just a couple of questions for now as I am working and won't be able to get back to this until later tonight. I also have some thoughts on your irrigation system. I can't find the pump online. Are you able to find and post the pump tech specs for me thanks? What size are the pit's inflow and outflow (overflow) pipes? The pipe that water pumps through from the pit to the tank looks like a 32mm PVC pressure pipe. Is it? This has an internal diameter of 37.5mm if it is a class 12. I assume that this connects to the pipe that rises vertically to the top of the tank. What size and type of pipe is this and where (distance) do the two pipes connect? How important is it that you maximise rainwater collection? 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: Bennie and Lisa's Landscape Project - Let the fun begin 7Apr 05, 2013 4:06 pm SaveH2O Just a couple of questions for now as I am working and won't be able to get back to this until later tonight. I also have some thoughts on your irrigation system. I can't find the pump online. Are you able to find and post the pump tech specs for me thanks? What size are the pit's inflow and outflow (overflow) pipes? The pipe that water pumps through from the pit to the tank looks like a 32mm PVC pressure pipe. Is it? This has an internal diameter of 37.5mm if it is a class 12. I assume that this connects to the pipe that rises vertically to the top of the tank. What size and type of pipe is this and where (distance) do the two pipes connect? How important is it that you maximise rainwater collection? Hi SaveH20, Here's a link to the pump: http://www.davey.com.au/site/DefaultSite/filesystem/documents/datasheets/DPM124-3%20D15VA_25VA_40VA.pdf The inflow to the pit is 90mm stormwater PVC pipe. The outlet to the tanks is 40mm PVC pipe. The overflow of the stormwater (if the pump is non-operational due to power outage say) is 90mm. The ring-main (40mm Poly all the way around) will have a combined length of 150metres with the furthest point being approximately 72metres away from the actual pump itself. Interested to hear your thoughts about the irrigation. I seriously thought I was doing the right thing here in setting up these tanks. From our perspective it is important to maximise our rain water collection. As can be seen in the photo of the tank, I'll say again,the join is temporary, it's only there in place at the moment to equalise the tanks with the water coming in. From a irrigation pump perspective though we've been recommended this : http://www.davey.com.au/site/DefaultSite/filesystem/documents/datasheets/D856_HS50-05_06_HS60-06_08.pdf The pump hasn't been purchased yet whilst we work out the rest of the garden (that is, get it's soil right! . The pump will be located beside the sump pit up against the barn wall. I've included a plain version of the site layout with exact measurements if this helps you in regards to your irrigation thoughts Thanks mate. Re: Bennie and Lisa's Landscape Project - Let the fun begin 8Apr 05, 2013 11:27 pm Hi Bennie, There are a number of issues with the rainwater harvesting system and I will give a break down. You might want to get a cut lunch, a coffee and a calculator first! Unfortunately, the negatives have to come first but I will explain them so that you can understand the parameters we need to operate within. RAINFALL AND DESIGN The first thing to do when designing a rain harvesting system is to calculate the applicable flow rates during a 1:20 Average Recurrence Interval (ARI). A 1:20 ARI is used to determine eaves gutter roof drainage compliance and so the inflows, tank overflows and everything else need to be determined for full tanks during a 1:20 ARI as a minimum. A 1:20 ARI happens much more frequently that once every 20 years and it is based on the average rainfall over a 5 minute duration. For example, The Melbourne 1:20 ARI is 130 mm/hr based on an average rainfall of 2.17 mm of rain per minute for a 5 minute duration. When I design a system, I always add 50% to the calculations. A 1:100 ARI is about 50% greater and box gutters are (or at least should be) required to drain during a 1:100 ARI. The area I live had a 1:500 ARI in Jan or Feb 2011. Your area's (Bacchus Marsh) 1:20 ARI is either 130 mm/hr or 120 mm/hr. For our examples, we will use 120 mm/hr as this is a simple 2mm per minute. ROOF CATCHMENT AREA 344 sq m PLUS an additional 35 sq m to be later plumbed to an existing storm water drain. I am assuming at the moment that this will also divert to the pit. YES/NO? 344 sq m harvested during a 1:20 ARI is 688 litres per minute in your area. INFLOW PIPE TO PIT 90mm PVC storm water pipe. This pipe comes in varying wall thicknesses that are 1.35mm, 1.5mm, 1.8mm, 1.9mm and 2.5mm. The common use ones are 1.8mm and 1.9mm. This pipe, apart from the 2.5 mm wall version, is very flimsy and should not be buried, particularly if you have reactive soil. The Australian Standards actually indicate in AS/NZS 3500.3:2003 Section 3, table 3.3 that it should not be used as a 90mm downpipe but it is okay to substitute for an 85mm or smaller round downpipe. The standards are ignored for this pipe! Nevertheless, our focus is on flow rates. 90mm PVC storm water pipe is measured as an outside diameter, the common use 1.9mm wall pipe is actually 86.2 mm internal diameter (ID). This gives it an internal volume of 5.838 litres per metre. This means that during a 1:20 ARI, the 688 litres per minute flow rate is equal to the volume of not quite 118 metres of 90mm storm water pipe. This means that the water would be blasting into the pit at almost 2 metres per second! PIT OVERFLOW PIPE The 90mm pipe could not drain at anywhere near 688 litres per minute. PUMP FLOW RATE The pump's flow chart shows 200 lpm with a 3 metre head but the pipe and fittings friction losses also have to be added as their equivalent head loss. The pit itself shows two 45 degree 40mm elbows (that are good for high velocities) and a 90 degree 40mm elbow. If the pipe and fittings added 1 metre to the head loss, then the pump will only deliver 160 lpm with the 4 m head loss. Of interest, the ID of 40mm class 12 PVC pressure pipe is 42.8m, giving it an internal volume of 1.439 litres per metre. At 200 lpm, water would flow through the 40mm pipe at over 2.3 metres per second. EDITED: Had accidentally written litres instead of metres per second. Pit pumps should be in tandem to avoid constant stop/starts as frequent cycling can burn out motors. I see it all the time. If you had light rainfall of lets say .3mm per minute (3mm in 10 minutes), the inflow would be 344 sq m of roof x .3 = 103 litres per minute. This would cause frequent cycling. Dual pumps are also regulated (where regulation is applicable) to alternate start ups so as to prevent frequent cycling. During a power failure or if the single pump breaks down, none of the water will be harvested. Even if the pump operated at 200 lpm (which it won't), rainfall in excess of .6 mm per minute will not be collected. (344 sq m x .6 = 206 litres per minute). PIT Small pits have little mitigation when the pump is unable to handle heavy rain. The inflow minus the total flow of the pump and the overflow pipe will be excess water that will overflow the pit. You need to know the volume of water between the 'stop' point (as shown in one photo) and the top of the overflow. This will allow you to fiddle around with different inflow scenarios to determine cycling times. The inflow during heavy rain will create significant disturbance and I am hoping that this won't toss the switch around and result in it cycling. I haven't heard of this happening but I don't have a lot to do with pumps. The pit will also need to be mosquito and vermin proofed. A pedestrian cover is also a good idea. Pits should not retain water but most do. During periods of low rainfall, a pit can become super stagnant and this water will be pumped into the tank the next time it rains. These issues can be easily overcome but I will wait for any questions before going further. IRRIGATION With the irrigation system, I always gravity feed whenever possible. To do this, you use a main feed line (poly pipe) and branch gravity fed drip hoses off it or else branch smaller poly pipe off the main line and gravity fed drip hoses off the branch lines. Wherever possible, the drip lines should be looped. Gravity fed drip hoses are much different to low pressure drip hoses as the drippers are larger. A gravity fed drip hose emitter drips at 2 lph. This gives the best soil hydraulic conductivity. In my garden, I often give my larger shrubs and trees a watering after a light rainfall as I figure that a good watering then is better than a meagre one from light rainfall and a rationed one later on. You can supply a suitable main line with very little head pressure. Basically, you need x 4 the head to double the flow rate and so if a tank can provide a suitably sized main line with let's say a 250mm head, you would need a 1 metre head to double the flow rate. The flow rate is only applicable to what is being used: if the mainline supplies the branch lines with constant pressure, then the head pressure is academic. You mentioned using 40mm poly, I assume you intend using Green Stripe. This is rural poly and it is measured as an ID. A 100 metre length of 40mm poly pipe will flow at 20.7 litres per minute with a .25 metre head. Note that this is an optimal flow rate; deviations and undulations will add to the friction loss and so you should only bank on maybe 19 lpm. It should be noted that your tanks are also on a raised base. You should not try to water everything at once as even 20 lpm is 1,200 litres per hour. Branch lines fitted with inexpensive inline taps are a good idea as you can isolate different sections when needed. When you have 2 or more tanks, you should always use them as a settling system, that is: feed into one tank only and draw water from the other tank. This will supply high quality clean water to the drip hoses. 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: Bennie and Lisa's Landscape Project - Let the fun begin 9Apr 06, 2013 10:05 am SaveH2O Hi Bennie, There are a number of issues with the rainwater harvesting system and I will give a break down. You might want to get a cut lunch, a coffee and a calculator first! * INSERT SPEECHLESS - JAW DROP HERE * Oh my..... What a post.... SaveH2O thanks a million for your concise explanation of water dynamics... It appears that my system isn't that good at all. What startles me more though is the 'professional advice' sought about the system and the professionals explaining that the system would cope. Originally they recommended me a much smaller pump but I decided at the time to go with something larger to cope with the heavier rains. You speak about the heavy rains of Jan / Feb 2011. My goodness I remember those rains and ALL of the gutters were overflowing. Plus due to the design of our house the previous owner when adding the pergola means that the gutters will naturally overflow anyway because putting it simply, it's missing an additional down pipe because of the increased roof area. However that can't be changed. I'm sorry I had to laugh when you said, 'The negatives have to come first ...' I got to the end of your post and thought.. Bugger he didn't really say any positives about the current setup.... However now with some knowledge we can work at creating something that will overcome (now glaring obvious) shortcomings. You know I always had this alarm bell slightly going off in my mind about the system. I've been hanging out for the rain to fall (HEAVILY) so I can get down to see how the pump is coping. A few times it's been fairly heavy and the system has worked ok. But it's experienced nothing like the deluge of the rain back in Jan 2011. All your flow rates make sense from a mathematics perspective. I said to Lisa I wish I knew the maths in which to work it out though. You've supplied that data but that is what shocks me so much. The system it it's present state is only a 1/3rd sized big enough to cope with a 688 litres per minute into the pump. To answer your question, the additional pergola storm water run off will divert to the PIT. I've dug the trench (my back is sore) and I'm not going to fill it in! Lol... Yes, I want to maximise potential but obviously some work needs to be done down at the pit. Something I didn't think about is now the obvious, when the tanks are full or the pump isn't working that little 90mm pit overflow has to be able to cope with potentially 688 litres per minute. That simply ain't going to happen. Now to make matters worst, we've got increased head pressure here SaveH20. The house is approximately 40 metres away from the pit. We'd have a drop of approximately 2.5 metres from the lowest collection point of the house to the pit. Wouldn't this downhill force lead to greater head force??? From a kinematic (speed) perspective??? It would be blasting into the pit.... Sigh... So then what happens.. The 90mm can't cope. So basically the PIT overflows.... Big time....... Not exactly what I want... The Pump / PIT What's your thoughts here? We actually had the plumber come in all day with the backhoe, excavate the pit hole etc.... Divert the storm water into the pit etc.. Now... It actually gets worst, because the plumber had done it when I wasn't looking he's actually sent the tank overflow back into the barn collection point which if course goes into the sump pit. Not a good design at all. A quick clarification, I forgot to mention the barn, we're collecting off that as well. However the calculations of roof area are still the same, I'd aggregated the two together. I mentioned to the plumber at the time after the install had taken place that I didn't think it was a good idea to send the overflow from the barn back into the sump pit as #1 Would be causing the pump to cycle more often. #2 If the pump was turned off then the poor little 90mm pit overflow would be really struggling. I can measure the inflow and overflow points for you if that helps but my gut feel is that we need to do something a little more drastic here. So my learned friend, what the hell do I do???? A simple idea of water collection from the roof has suddenly got way more complex. If I had my own way the water would be gravity fed into the tanks, alas the inlet height of the tanks is 1/2 way up our house and simply wouldn't work. The sump pit solution is definitely what I want to do, I just never realised all the complications that go with it. Regarding Irrigation : I can't gravity feed my block slopes down from the top to the back.... And to be honest, let's concentrate on fixing the rain harvesting situation first. My partner Lisa has just sent me a txt message seeing your post and gone... MY HEAD IS SPINNING... and i'm sure she's also thinking, what the hell have we done.... I joined this forum to learn about growing veggies and grass and here I am back at the basics of water collection! lol! Thanks in advance SaveH2O..... I see you're in Melbourne... Feel like a drive to the Marsh???? hehehehehehe Cheers. Bennie! Re: Bennie and Lisa's Landscape Project - Let the fun begin 10Apr 06, 2013 1:42 pm Hi Bennie & Lisa. I have to make this quick as I am on my lunch break and I have a heap to do. I am in and out though but this could take a few 'sittings'. -Bennie- What startles me more though is the 'professional advice' sought about the system and the professionals explaining that the system would cope. Originally they recommended me a much smaller pump but I decided at the time to go with something larger to cope with the heavier rains. Plumbers and "professional" tank installers rarely know anything about installations. The problem is that they think it is easy and it is the consumer that always ends up with a sub standard and more often than not overpriced install. Plumbers are not trained in rainwater harvesting and yet the plumbing industry regulations only lets untrained plumbers do the installing! I suppose that you also had to pay for a compliance certificate! There is every chance that your installation is not compliant as the pit and the water tank and its overflow are part of the storm water system's flow path. As such (in my belief), the pit and pump come under AS/NZS 3500.3:2003 Section 9 PUMPED SYSTEMS. 9.2 GENERAL states: Pumped systems are for areas normally less than 2,000 sq m where it is not possible for the stormwater to be discharged by gravity through the available gravitational point of connection. There are a number of regulations that I can detail where your system does not comply with the standards. I didn't mention it first up in case it was a DIY. I will check the regs when I get some time. Nevertheless, what is there is what has to be worked around. With the pump you have, you would lose water whenever the rainfall exceeds .5mm per minute and even less than this once the additional 35 sq m of harvest area is plumbed. It would be worse with a smaller pump but a smaller pump would not cycle as much. This is why they regulate the use of two pumps. With our (Melbourne) rainfall, 90% is either drizzle, showers of varying intensity or very light rain but when we do get heavy rain, it is generally localised and intense. Unfortunately, I don't have statistics re the percentage of annual rainfall that occurs during the varying intensities but you would obviously be losing a lot of yield during heavier rainfall because of the pit and pumping system. I have however done years of flow testing with one downpipe at my place and I know that for a minimum 90% of the Melbourne 'rainfall' periods, 'rainfall' per 10 sq m of roof harvest area produces between .1 to 1 litre per minute. Taking a median of .5 lpm which I believe would be fairly accurate, this equates to .05 mm of "rain" per minute or 3 mm per hour on average for 90% of the time. Lighter rainfall however also results in most of the annual yield loss as about one third of Melbourne's annual rain days produce less than 1mm of rain. Most of this evaporates. EDITED: Checking the Bureau of Meteorology 1855 - 2012 statistics shows that the annual average of 149.6 rain days recorded for Melbourne, 49.2 days had rainfall of 1 mm or less. One thing that could be done is to raise the top of the overflow maybe 100mm. It would be much better if the top was a bell mouth. There are several things that can be done to prevent yield loss but I really need to know the gutter and tank overflow levels. I will be out at Pykes Creek from 26-28th of this month looking at rooster tails and I could call in and have a look on the way home. I strongly prefer to post solutions in the forum as other people will also benefit but it can be difficult without being onsite. Your situation is actually very common. If I discussed solution options with you, I feel confident that you would post the end result in the thread so that others might also benefit. If you go through my posts, you will find some rainwater harvesting threads that might also interest you. -Bennie- You speak about the heavy rains of Jan / Feb 2011. My goodness I remember those rains and ALL of the gutters were overflowing. Plus due to the design of our house the previous owner when adding the pergola means that the gutters will naturally overflow anyway because putting it simply, it's missing an additional down pipe because of the increased roof area. However that can't be changed. Yes it can! -Bennie- Now to make matters worst, we've got increased head pressure here SaveH20. The house is approximately 40 metres away from the pit. We'd have a drop of approximately 2.5 metres from the lowest collection point of the house to the pit. Wouldn't this downhill force lead to greater head force??? From a kinematic (speed) perspective??? It would be blasting into the pit.... What's your thoughts here? The head will only be at the height applicable to the flow rate, the down pipe will not be full. A 86.2 mm ID PVC pipe flowing with a 2.5 metre head over 40 metres will have a theoretical flow rate of 890 lpm at a velocity of 2.54 metres per second. Your system will never achieve this as it would carry entrained air, there are other flow path friction losses plus the top few hundred mm will have a lot of bubbles and this depletes head. At a velocity of 2.54 metres per second, it would also have low vapour pressure and this is a very big NO NO but I have something in mind here. The 90mm storm water pipe is not rated for pressure use and it should not have been used. The plumber is a dill. I am also sure that if the block is greater than 1,000 sq m, then 100 mm DWV pipe has to be used. I don't have time to check now. -Bennie- Now... It actually gets worst, because the plumber had done it when I wasn't looking he's actually sent the tank overflow back into the barn collection point which if course goes into the sump pit. Not a good design at all. I mentioned to the plumber at the time after the install had taken place that I didn't think it was a good idea to send the overflow from the barn back into the sump pit as #1 Would be causing the pump to cycle more often. #2 If the pump was turned off then the poor little 90mm pit overflow would be really struggling. Ah yes, the plumber always knows best. There is absolutely no excuse for this but the 'solution' obviously came about because he had forgotten about the tank's overflow. Can you do a line of sight measure from the slab to judge the barn's gutter (sole) height rather than from the ground? Is the bottom of the barn's lowest gutter higher than the bottom of the tank's overflow and if so, what is the distance? This needs to be fairly accurate. How much excess room do you have where the other two tanks are? What size downpipes do you have, 90 or 100mm? -Bennie- I joined this forum to learn about growing veggies and grass and here I am back at the basics of water collection! lol! Don't worry Bennie, by the time I'm finished, you will be advising plumbers! Read this thread... viewtopic.php?f=35&t=60789 Edited rainfall stats on 18/04/2013 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: Bennie and Lisa's Landscape Project - Let the fun begin 11Apr 07, 2013 9:55 am SaveH2O Hi Bennie & Lisa. I have to make this quick as I am on my lunch break and I have a heap to do. I am in and out though but this could take a few 'sittings'. Mate... All your hard work in posting to this thread has been fantastic.. I'm hoping other viewers are getting as much out of it as myself... and hoping they won't be making as you state, 'common mistakes!' Quote: Plumbers and "professional" tank installers rarely know anything about installations. The problem is that they think it is easy and it is the consumer that always ends up with a sub standard and more often than not overpriced install. Plumbers are not trained in rainwater harvesting and yet the plumbing industry regulations only lets untrained plumbers do the installing! I suppose that you also had to pay for a compliance certificate! Well, I'm finding that out the hard way aren't I For interest's sake I rang my local council and told them of my plans for the storm water intercept and asked them about the legality of this action. They said to me, 'You can do anything you like with your storm water. It's entirely up to you and your responsibility, however if it goes off the property it needs to go into your legal point of discharge. Of which I asked them where it was of which they said they had no plans.. .<that's another story all together> Re: The overpriced install. Well it hasn't been expensive SaveH2O. Everything that we have been able to do ourselves we have. We found the storm water pipe. We hired the backhoe. Told the plumber exactly what we wanted (except for the barn overflow stuffup however that can potentially by fixed..... There is no compliance certificate. Quote: There is every chance that your installation is not compliant as the pit and the water tank and its overflow are part of the storm water system's flow path. As such (in my belief), the pit and pump come under AS/NZS 3500.3:2003 Section 9 PUMPED SYSTEMS. 9.2 GENERAL states: Pumped systems are for areas normally less than 2,000 sq m where it is not possible for the stormwater to be discharged by gravity through the available gravitational point of connection. Ouch.... Again...... However if the pump is off (and we know that the discharge pit overflow of 90mm is not enough is still in affect, gravity feed..... Quote: There are a number of regulations that I can detail where your system does not comply with the standards. I didn't mention it first up in case it was a DIY. I will check the regs when I get some time. Nevertheless, what is there is what has to be worked around. Thanks mate, that would be fantastic. Quote: With the pump you have, you would lose water whenever the rainfall exceeds .5mm per minute and even less than this once the additional 35 sq m of harvest area is plumbed. It would be worse with a smaller pump but a smaller pump would not cycle as much. This is why they regulate the use of two pumps. I've been trying in my head to think about how this two pump design would work. As yet I haven't worked it out. lol! The thing is though, here I was thinking that my pump was actually in the middle of the road.... When in reality it's quite a small pump.... Quote: With our rainfall, 90% is either showers of varying intensity or light rain but when we do get heavy rain, it is generally localised but intense. Unfortunately, I don't have statistics re the percentage of annual rainfall that occurs during the varying intensities but you would obviously be losing a lot of yield during heavier rainfall. I have however done years of flow testing with one downpipe at my place and I know that for a minimum 90% of the Melbourne rainfall periods, "rainfall" per 10 sq m of roof harvest area is usually between <1 to 4 litres per minute. Taking a median of 2.2 lpm which I believe would be fairly accurate, this equates to .22 mm of "rain" per minute on average for 90% of the time. Lighter rainfall however also results in most of the annual yield loss as about one third of Melbourne's annual rain days produce less than 1mm of rain. Most of this evaporates. Interesting facts.... Every time it's being raining over the past 3 weeks and I've been home I've headed down to the pit to see how the pump is going. Your right about the evaporate effect. If it hasn't rained for a week it takes ages for the water to come down and in a light rain all your really talking about is a trickle. One of the things I haven't done yet though is to purchase a rain gauge for the tank so I have no idea how much water is actually in the tank. However I'll be buying one soon... Any recommendations??? Quote: One thing that could be done is to raise the top of the overflow maybe 100mm. It would be much better if the top was a bell mouth. I've got something to show you in a moment... A video of a rather heavy downpour !!!! Quote: There are several things that can be done to prevent yield loss but I really need to know the gutter and tank overflow levels. I will be out at Pykes Creek from 26-28th of this month looking at rooster tails and I could call in and have a look on the way home. Thats really, really kind of you. Thank you ever so much. Your thoughts and words and obvious experience are really appreciated mate. Thanks a million. My intentions with the system are obviously good, for our plans for the garden, the less environmental impact of rain harvesting off your own roof. Which I still think is pretty cool getting all this, 'Free Water!'. I get excited about it. Plus with the solar, we're well on our way to become more sustainable. Over the past six months we've becoming quite green in the family. I actually work in Information Technology but love getting my hands dirty. Outdoors are great and I do a LOT of running around the Lerderderg State Forest. Is great where we live! Quote: I strongly prefer to post solutions in the forum as other people will also benefit but it can be difficult without being onsite. Your situation is actually very common. If I discussed solution options with you, I feel confident that you would post the end result in the thread so that others might also benefit. If you go through my posts, you will find some rainwater harvesting threads that might also interest you. Absolutely... Anything that I learn I'm more than happy to share with others. Have no doubt there, a point of view, an opinion posted is a fantastic thing. The ability to learn through others on the web, seeing a visual demonstration on youtube tells a thousand words compared to reading it in a book! It's working out the good and bad that can sometimes be difficult! I'm happy though that I'm giving it a go! I'm not going to let life go by and say... Gee, I wish I'd done that! I'm lucky as well that Lisa and I have the same passions which is live life to the full! Plus be a great example to the kids! Quote: -Bennie- You speak about the heavy rains of Jan / Feb 2011. ... However that can't be changed. Yes it can! I don't think so mate.... I'll find a photo / video of why I think it would be very difficult to fix the gutters here. They're jammed in against the pergola structure in a box like shape. There's no room to go down or out, even going up is a challenge with the pergola perspect. Quote: The head will only be at the height applicable to the flow rate, the down pipe will not be full. A 86.2 mm ID PVC pipe flowing with a 2.5 metre head over 40 metres will have a theoretical flow rate of 890 lpm at a velocity of 2.54 metres per second. Your system will never achieve this as it would carry entrained air, there are other flow path friction losses plus the top few hundred mm will have a lot of bubbles and this depletes head. At a velocity of 2.54 metres per second, it would also have low vapour pressure and this is a very big NO NO but I have something in mind here. Wow..... Your explanation makes sense... I'm presuming with all this information that you're background is rain harvesting??? The maths appears to be spot on as well. For me once something is actually said, it makes sense. I thought I had a good idea of volumes but seeing a practical example brings it all together... Interested in your ideas of course Quote: The 90mm storm water pipe is not rated for pressure use and it should not have been used. The plumber is a dill. I am also sure that if the block is greater than 1,000 sq m, then 100 mm DWV pipe has to be used. I don't have time to check now. However mate, this is the original storm water discharging from the property and going to the Western Water main storm water drain. The house was built 10 years ago and they're using 90mm storm water... You'll be happy??? to know that aggregate was around the storm water / sewer pipes when we dug down.... Quote: Ah yes, the plumber always knows best. There is absolutely no excuse for this but the 'solution' obviously came about because he had forgotten about the tank's overflow. I should have forced the issue right then and there. But stupid me didn't push even though my head had alarm bells ringing!! Sigh..... Quote: Can you do a line of sight measure from the slab to judge the barn's gutter (sole) height rather than from the ground? Is the bottom of the barn's lowest gutter higher than the bottom of the tank's overflow and if so, what is the distance? This needs to be fairly accurate. Yes.... The lower part of the barn is exactly 2.5metres <where the gutter is> The inflow of the tank is 2.83 metres. Which obviously means I can't go from the barn directly into the tank.. So it heads to the sump pit instead. Quote: How much excess room do you have where the other two tanks are? If you look at the blank sketch up design you can see from the top down view the spaces around the tank. I've also taken a quick google sketch up shot of the tanks to give you an idea of what it looks like. Note, these measurements are EXACT! and this : Does this help??? Quote: What size downpipes do you have, 90 or 100mm? 90mm mate.... Quote: -Bennie- I joined this forum to learn about growing veggies and grass and here I am back at the basics of water collection! lol! Don't worry Bennie, by the time I'm finished, you will be advising plumbers! Read this thread... viewtopic.php?f=35&t=60789 Hehehehehe. Thanks for ALL your help so far mate... As said above, I really appreciate it. Out of interest a LOT of people at work, friends etc are interested to see how our rain harvesting project is going! Telling them about my journey is something that I hope helps them in their own endeavours. Now the interesting bit!!!!!! The video promised!! I took this yesterday when for some bizarre reason it decided to rain over Bacchus Marsh http://www.youtube.com/watch?v=-9D02KHCH7E This is the pump not coping... For interest's sake our gutters also overflowed at the pergola... We get this type of rain during summer a fair bit..... What's your thoughts??? What worries me is that the sump pit will most definitely FLOOD big time if the power is off and the pump not operational Talk soon! If you require any other facts I'll provide them ASAP! Cheers Bennie Re: Bennie and Lisa's Landscape Project - Let the fun begin 12Apr 07, 2013 2:47 pm -Bennie- Originally they recommended me a much smaller pump You know I always had this alarm bell slightly going off in my mind about the system. I've been hanging out for the rain to fall (HEAVILY) so I can get down to see how the pump is coping. I said to Lisa I wish I knew the maths in which to work it out though. You've supplied that data but that is what shocks me so much. The system it it's present state is only a 1/3rd sized big enough to cope with a 688 litres per minute into the pump. We actually had the plumber come in all day with the backhoe, excavate the pit hole etc.... Divert the storm water into the pit etc.. Now... It actually gets worst, because the plumber had done it when I wasn't looking he's actually sent the tank overflow back into the barn collection point which if course goes into the sump pit. I mentioned to the plumber at the time after the install had taken place that I didn't think it was a good idea to send the overflow from the barn back into the sump pit If I had my own way the water would be gravity fed into the tanks, alas the inlet height of the tanks is 1/2 way up our house and simply wouldn't work. Hi Bennie & Lisa. A few more questions before I get down to the nitty gritty...which will have to be in the next post as I am under the hammer today and I need to check a few things. Apart from consulting the plumber, was anybody else involved in 'designing' the system? How far above the bottom of the tank's overflow pipe is the house gutter's sole? I wonder if this was even calculated. With the big roof harvest area, hydraulic calculations needed to be done. This not only applies to the suitability of the stormwater pipe but also to the pump they originally recommended. If the originally suggested smaller pump was good for let's say 140 lpm, it would not be able to cope with a rain intensity of more than .4mm per minute. (344 sq m x .4mm = 137.6 lpm. Re the current pump, was it explained to you that additional friction losses for pipe fittings and pipe length also have to be added to the head loss or were you told that you would get 200 lpm? A lot of people are given wrong information about pumps and this scenario is very common. Does your current pump use 40mm pipe the entire length or does it increase to a larger size? Just got back and noticed your latest post. I have to correct something. When I calculated the flow rates through the 90mm pipe, I did it as a total of the house and the barn's roof harvest areas. I noticed the (second) upper drain pipe coming into the pit but didn't factor that as coming from the barn as I had (now obviously) wrongly assumed that the newly trenched pipework would be connected to this pipe so as to avoid overloading the existing 90mm pipe. I have taken it that the pergola was installed by the previous owner as per... -Bennie- Plus due to the design of our house the previous owner when adding the pergola means that the gutters will naturally overflow anyway because putting it simply, it's missing an additional down pipe because of the increased roof area. As per the above, I am interested in knowing the following as I seem to have missed something. If the pergola is already there, then where is the gutter draining to and why are you trenching for new pipe work? Nothing like being on site! I won't have time to properly look at the diagrams in you last post and do calculations until much later tonight or even tomorrow night but as you wanted to gravity drain to the tanks, did you talk this over with the plumber or others or did you (on your own) assume that you wouldn't be able to do this? Were the tanks ordered prior to any consultation or were the tanks ordered after being given "professional" advice. At this stage, I will go through some background very quickly so I can send this but first some info re fitting a bell mouth to the pit's overflow pipe. Vertical drain pipes drain as weir flow and you will notice that this generates an annular vortex. The vortex may not appear that large when viewed from above but it spirals an air core down the pipe that also causes water in a round pipe to spiral. For this reason, a down pipe, unless blocked or flooded, will never have less than 2/3rds air. The air core is also a very large and buoyant physical barrier. If the head is of sufficient depth or the pipe is otherwise flooded, the vortex can break. When this happens, the head needs to overcome the buoyancy of the air core and purge the pipe. Once this happens, the drain pipe will flow much faster as it will be full of water and travelling with increased velocity due to the generated head pressure. One way of doing this is to add a bell mouth as the bell mouth drains a larger surface area to a smaller area. If you have heavier rain over the next few weeks, having a bell mouth could easily be the difference between the pit overtopping or the discharge pipe coping. Some personal information; I research and develop new products and over the past few years I have concentrated primarily on rainwater harvesting and some plumbing products. I also design syphonic rainwater harvesting systems and I have also developed two new methods of harvesting rainwater. To see a 4 tank diagram of a version developed for farmers and others with big tanks, see the link below. http://imageshack.us/a/img407/6228/tanksfinal.jpg The thread that discussed this system is in the next link below. Note that a different overflow set up was originally devised during the first two pages but the hydraulic calculations devised to overcome a low head problem remained the same. viewtopic.php?f=35&t=60317 I mention this as per the following. Diverting harvested rainwater up a vertical riser is very inefficient. Inadequate flushing velocities are discussed in the linked thread but for your pumped system, it means that your pump is always operating with the same hydraulic restrictions regardless of how full the tank is! This also means that the vertical riser's outlet that discharges to the tank's top meshed inlet is higher than the water level is even when the tank is full (to the bottom of the tank's overflow pipe). This is wasted energy and lower flow rates than would otherwise be possible if the pump fed to a lower inlet. Another problem however is that if your pump diverted water to a 40mm inlet fitted 100-150mm above the bottom of the tank, it would be diverting unfiltered water. Ideally for any system and particularly a pumped system, you should have leaf diverters fitted. I have seen stones and even bones washed into pits. One of the things that alerted me to problems with your system was the photo with Lisa in your first post as it showed that you did not have leaf diverters fitted. While the pump ingesting a bit of bone is improbable, it could take in large grit and organic material as it is a dirty water pump. As an aside, years ago one of my downpipes was blocked by a bone at the second elbow and since then I regularly check my gutters for the bones that are left by crows that steal the neighbours dog food. The problem that has to be overcome with your system is that unless the pump can cope with the inflow, you lose substantial yield. Fitting a bigger pump is expensive plus it would only be on for very short periods but frequently cycle during your normal rainfall pattern. Not good plus I have major concerns about the likely frequency of your current pump cycling at any rate. One solution is to divert a lot of the water away from the pit and directly into an inlet valve fitted 100-150mm above the bottom of the tank. This would retain the pit but allow the pump to cope a lot better. When designing this flow path method, it must be factored for a full tank. Different tank levels provide variable head pressure; that is... lower water level = greater head = higher available flow rates. This method would however involve additional plumbing and for practical purposes, this could "only" be done from the barn as the pipe coming from the house cannot feed both the tank and the pit. I emphasised "only" as there is a method but it involves a proprietary product. This further solution would be best used to divert house roof water to another tank sited near the trees. An overflow return pipe would not be needed as the tank would only fill to just below the overflow outlet and the water would then divert back to the storm water pipe. This tank could then be used for gravity watering plus it could also be refilled from the larger tanks when they have sufficient storage levels. Diverting water from the barn depends on the levels of the gutter's sole and the bottom of the tank's overflow pipes. If there is insufficient head, then you would be looking at diverting to another lower tank that had a submersible pump to pump the water to a bigger tank. That smaller tank would need to have adequate mitigation and an overflow provision to cope with a power failure. These are just some open thoughts and information to give you something to go on. I will try and find some time later tonight or most likely tomorrow night to go over the diagrams and information in your last post. 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: Bennie and Lisa's Landscape Project - Let the fun begin 13Apr 07, 2013 4:10 pm What is the height from the slab to the bottom of the tank's overflow pipe? 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: Bennie and Lisa's Landscape Project - Let the fun begin 14Apr 08, 2013 3:32 pm Hiya H20, SaveH2O Hi Bennie & Lisa. A few more questions before I get down to the nitty gritty...which will have to be in the next post as I am under the hammer today and I need to check a few things. Apart from consulting the plumber, was anybody else involved in 'designing' the system? How far above the bottom of the tank's overflow pipe is the house gutter's sole? I wonder if this was even calculated. A number of people were involved in the design of the system. #1 The local Farm Supply Centre where the tanks were puchased from. #2 Irrigation specialist store down in Geelong. One of their designers spec'd the system out #3 The plumber and of course myself, thinking I was doing the right thing. To answer your question about the tank's overflow pipe to the house's gutter (sole ??? - As in where the pipe goes into the ground?? - Would be hard to fathom as it's about 30 metres away from the house and it slopes down but as a *guess* it would be approximately almost level I'm guessing. I'll get home tonight and try and work it out. Or have I totally got that wrong??? SaveH2O With the big roof harvest area, hydraulic calculations needed to be done. This not only applies to the suitability of the stormwater pipe but also to the pump they originally recommended. If the originally suggested smaller pump was good for let's say 140 lpm, it would not be able to cope with a rain intensity of more than .4mm per minute. (344 sq m x .4mm = 137.6 lpm. Re the current pump, was it explained to you that additional friction losses for pipe fittings and pipe length also have to be added to the head loss or were you told that you would get 200 lpm? A lot of people are given wrong information about pumps and this scenario is very common. Having read my own documentation I realised that there would be some loss from a pumping perpsective but the irrigation store that sold me the submerisible pump clearly stated it would be able to do at least 200 litres per metre with a measured head of 3.0 metres. Here's some facts about the tank: Code: Polymaster : RWT22500 Litres/Gallons: 22,500 (5000 gal) Diametre: 3.56 m (11’8”) Inlet Height : 2.47 m (8’1”) Overall Height: 2.8 m (9’2”) Tank Base : 100mm Sump Pit Depth : 800mm So inlet height + base + sump pit depth + 50mm to get over the top of the inlet value = 2470 + 100 + 800 + 50 = 3420mm So 3.42 metres from the bottom of the sump pit to the top of tank. Does this information help mate??? SaveH2O Does your current pump use 40mm pipe the entire length or does it increase to a larger size? 40mm the whole way.... SaveH2O When I calculated the flow rates through the 90mm pipe, I did it as a total of the house and the barn's roof harvest areas. I noticed the (second) upper drain pipe coming into the pit but didn't factor that as coming from the barn as I had (now obviously) wrongly assumed that the newly trenched pipework would be connected to this pipe so as to avoid overloading the existing 90mm pipe. Sorry, that's my fault of not explaining the setup properly.... At the moment there are two separate water sources, the house and the barn. Both water sources at the moment head into the sump pit. SaveH2O I have taken it that the pergola was installed by the previous owner as per... -Bennie- Plus due to the design of our house the previous owner when adding the pergola means that the gutters will naturally overflow anyway because putting it simply, it's missing an additional down pipe because of the increased roof area. As per the above, I am interested in knowing the following as I seem to have missed something. If the pergola is already there, then where is the gutter draining to and why are you trenching for new pipe work? Nothing like being on site! Yes, the pergola was installed by the previous owner and even to my untrained eye and experience you can obviously see that the gutters will fail in a moderate storm. On Saturday's rain dump over Bacchus Marsh (in which the gutters overflower) we had an inch of rain in 2 hours. Obviously 5 min intervals were not ascertained which would have helped quite nicely with our calculations! Now to answer your question about the THIRD water source which is the north facing side of the pergola. Having done the measurements again.. I can guess there is actually about 30-40square metres of additional roof area. Note, this water is currently being drained to a little pissy 1,000 tank tucked behind the mural as a wet based system and is not hooked up to the storm water at all. Before I realised about the ramifications of the roof area but grandioise idea was to plumb this water instead to the 1,000 water tank to an existing storm water pipe. It would be a 'semi-wet' system with some water always being in place due to the lie of the land. Note.. I have dug the trench and was in the process of completing the install (before it bloody flooded me out).. That's right, Bennie digging a trench meant that it rained. I'm guessing SaveH20 that hooked the additional 30-40 square metre of water to the existing storm water is a bad idea??? I feel gutted though that I've spent the past week after work digging a 10-15 metre trench it would be heart breaking to fill this trench in which a pipe in it! lol!!! However I'll stop the work for the moment and will not connect.... Does the above make sense? What I might do is to put the infrastructure into a diagram in Google Sketch Up and show it to you via that way... SaveH2O I won't have time to properly look at the diagrams in you last post and do calculations until much later tonight or even tomorrow night but as you wanted to gravity drain to the tanks, did you talk this over with the plumber or others or did you (on your own) assume that you wouldn't be able to do this? Were the tanks ordered prior to any consultation or were the tanks ordered after being given "professional" advice. That's ok... Take your time, I'm not going anywhere mate.... I did talk over the design with the irrigation specialist and the plumber of who ALL said it was a great design. Blah..Blah...Blah.... I spoke to the farm supply centre about the tanks... The size and installation of the tanks was however my idea.. They're tucked out of view mostly and the storm water goes quite close etc.... SaveH2O At this stage, I will go through some background very quickly so I can send this but first some info re fitting a bell mouth to the pit's overflow pipe. Vertical drain pipes drain as weir flow and you will notice that this generates an annular vortex. The vortex may not appear that large when viewed from above but it spirals an air core down the pipe that also causes water in a round pipe to spiral. For this reason, a down pipe, unless blocked or flooded, will never have less than 2/3rds air. The air core is also a very large and buoyant physical barrier. If the head is of sufficient depth or the pipe is otherwise flooded, the vortex can break. When this happens, the head needs to overcome the buoyancy of the air core and purge the pipe. Once this happens, the drain pipe will flow much faster as it will be full of water and travelling with increased velocity due to the generated head pressure. One way of doing this is to add a bell mouth as the bell mouth drains a larger surface area to a smaller area. If you have heavier rain over the next few weeks, having a bell mouth could easily be the difference between the pit overtopping or the discharge pipe coping. Having done a quick search on google and understanding your own calculations I can clearly see from a fluid dynamics perspective of why this solution is so much better than a constant width pipe... Plus watching my own you tube video you can clearly see the agitation and vortex forming... SaveH2O Some personal information; I research and develop new products and over the past few years I have concentrated primarily on rainwater harvesting and some plumbing products. I also design syphonic rainwater harvesting systems and I have also developed two new methods of harvesting rainwater. To see a 4 tank diagram of a version developed for farmers and others with big tanks, see the link below. http://imageshack.us/a/img407/6228/tanksfinal.jpg The thread that discussed this system is in the next link below. Note that a different overflow set up was originally devised during the first two pages but the hydraulic calculations devised to overcome a low head problem remained the same. viewtopic.php?f=35&t=60317 Thanks for that. I've had a really good read through the thread and pretty much we're talking about the same thing. I really did think that this stuff wouldn't be that hard.. Nothing like hindsight hey??? SaveH2O I mention this as per the following. Diverting harvested rainwater up a vertical riser is very inefficient. Inadequate flushing velocities are discussed in the linked thread but for your pumped system, it means that your pump is always operating with the same hydraulic restrictions regardless of how full the tank is! This also means that the vertical riser's outlet that discharges to the tank's top meshed inlet is higher than the water level is even when the tank is full (to the bottom of the tank's overflow pipe). This is wasted energy and lower flow rates than would otherwise be possible if the pump fed to a lower inlet. That all makes sense... Why is this stuff so obvious when it's actually explained to you??? Sigh.... Another problem however is that if your pump diverted water to a 40mm inlet fitted 100-150mm above the bottom of the tank, it would be diverting unfiltered water. Ideally for any system and particularly a pumped system, you should have leaf diverters fitted. I have seen stones and even bones washed into pits. SaveH2O One of the things that alerted me to problems with your system was the photo with Lisa in your first post as it showed that you did not have leaf diverters fitted. While the pump ingesting a bit of bone is improbable, it could take in large grit and organic material as it is a dirty water pump. No.. we have zero leaf gutters.. Out of interest our intent was never to use the water for drinking/personal needs. However the toilet and washing machine have of course been considered.... SaveH2O The problem that has to be overcome with your system is that unless the pump can cope with the inflow, you lose substantial yield. Fitting a bigger pump is expensive plus it would only be on for very short periods but frequently cycle during your normal rainfall pattern. Not good plus I have major concerns about the likely frequency of your current pump cycling at any rate. How did I just know that having a bigger pump is not the solution here.... Sigh.. Lisa and I are of course on a budget like most people and we'd like to... invest in our garden etc.. But unless I get this rain harvesting system right then it will be to no avail. I just feel really disappointed with myself... I don't want the Taj Mahel but I want something that is going to cope. I obviously didn't consider a large roof area, large amount of rainful = HUGE amount of water heading out of the property... SaveH2O One solution is to divert a lot of the water away from the pit and directly into an inlet valve fitted 100-150mm above the bottom of the tank. This would retain the pit but allow the pump to cope a lot better. When designing this flow path method, it must be factored for a full tank. Different tank levels provide variable head pressure; that is... lower water level = greater head = higher available flow rates. This method would however involve additional plumbing and for practical purposes, this could "only" be done from the barn as the pipe coming from the house cannot feed both the tank and the pit. This solution I read about in your other thread... Very interesting.... My problem which is very obvious now is the full tank scenario.. At the moment I'm stuffed until this is fixed. I hear a ticking time-bomb clock from the back yard... Just a matter of time until it goes bang!!!! SaveH2O I emphasised "only" as there is a method but it involves a proprietary product. This further solution would be best used to divert house roof water to another tank sited near the trees. An overflow return pipe would not be needed as the tank would only fill to just below the overflow outlet and the water would then divert back to the storm water pipe. This tank could then be used for gravity watering plus it could also be refilled from the larger tanks when they have sufficient storage levels. Interesting thoughts..... I suppose I need to look at a solution that will work... SaveH2O Diverting water from the barn depends on the levels of the gutter's sole and the bottom of the tank's overflow pipes. If there is insufficient head, then you would be looking at diverting to another lower tank that had a submersible pump to pump the water to a bigger tank. That smaller tank would need to have adequate mitigation and an overflow provision to cope with a power failure. I'm going to need to look at the above paragraph a few times to make sense... lol!!!! SaveH2O These are just some open thoughts and information to give you something to go on. I will try and find some time later tonight or most likely tomorrow night to go over the diagrams and information in your last post. What is the height from the slab to the bottom of the tank's overflow pipe? Thanks for all your information so far. Really appreciate it mate. Re: The height question. I'll get home tonight and measure it... *whew*.... This is becoming a post and a half.... and I haven't even started on the soil conditioning yet... hehehehehehe! Thanks again. Bennie Re: Bennie and Lisa's Landscape Project - Let the fun begin 15Apr 08, 2013 6:30 pm Just a real quick reply for now to cover some basics. I will answer the rest later. It is always interesting to learn about the design process. Irrigation guys are usually clued up with flow rates and dynamic head. It is a surprise that you were not better advised. You have several options and I will discuss these with you when I pass through. Obviously there will be some costs and work involved as you will need a combination of fixes but it won't be too much. At least I'm free! Regardless of the final package, you will need to do most of the following (if possible)... Increase the pump's flow rate. The "measured head" is a total of the elevation plus pipe and fittings friction losses. Not much use having a "professional" quoting 200 lpm @ a 3 metre measured head if the elevation is 3.4 metres on its own! You just need to fit a 40mm inlet high up on the smooth part of the tank's wall at the bottom of the tank...if that makes sense. The efficiency gain will vary with the level of water inside the tank but with a 1/2 full tank, you should gain (approx) 60 lpm. Make sure that there is a check valve fitted! People sometimes think that the weight of the water in the tank will push against the water in the pipe but the water is hydraulically coupled and responds to pressure, not weight. For example, if you had a big 100,000 litre tank that was 4 metres tall, it would hold 100 tons of water when full but each 1 metre of head will only exert 9.8 kPa pressure or 39.2 kPa for 4 metres. I will mention here that when I posted... "lower water level = greater head = higher available flow rates" ...the greater head pressure referred to a charged infeed pipe. It would also apply to the dynamic head from a pump that fed to a low inlet rather than to the meshed inlet at the top of a tank. EDITED the above by adding the last line. Fit the bell mouth. This will improve drainage efficiency and raise the pit's water level before the overflow spills. See if you can increase the length of the float switch tether. This will delay the start up which in turn will reduce cycling. Do this after you fit the bell mouth. Divert some or all of the house water directly into one of the large tanks. This will depend on gutter levels and tank overflow heights. Diverting will be through a low inlet and this will automatically provide more head. Will need to evaluate and discuss on site but you have previously posted that there is a 2.5 metre slope from the house to the pit. If so and if the house gutters are let's say 2.4 metres high, the fall from the gutters to the pit is 4.9 metres. If the distance from the slab to the bottom of the tanks overflow outlet is let's say 2.2 metres, you would have a very substantial head even when the tank was full if you diverted to a lower inlet. The posted photos support your information. To confirm, just use a brick mortar line for the line of sight. Use another tank near the trees to divert house roof drainage. This will also save pump use when irrigating. The gutter's sole is the bottom of the gutter. The bottom of the tank's overflow is the bottom of the overflow outlet fitting. I would be surprised if I could not fix your overflowing gutter. It will cost about $30 for all parts and will take 1/2 an hour. One thing you need to consider is the amount of rain needed to fill the tanks and the winter time use of that water. Even with yield loss, 150 mm of rain would replenish both tanks. 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: Bennie and Lisa's Landscape Project - Let the fun begin 16Apr 11, 2013 4:10 am Bennie, As a matter of interest, did you buy the tanks and have the plumbing done after July 1,2012 and if so, did you claim a rebate? 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: Bennie and Lisa's Landscape Project - Let the fun begin 17Apr 11, 2013 7:42 am Morning SaveH20, Sorry for the delay in replying, quite busy over the past few days. Plus it was my Lisa and my anniversary yesterday For a quick update re: the trench and pergola hookup. I've decided to not hook it up until you drop past later this month. If it has to be taken apart anyway plus the increased roof area will further strain the sump pit / pump. Your comments re: weight vs water now makes perfect size. Thanks for the explanation. I was explaining it to my step son last night and he had a light bulb moment when he got it. What is more interesting is your comment about running the pipe directly into the lower part of the tank instead of up over the top. It never occurred to me that you could do this. Wow ! Even with the barn as well. That would be the ultimate wouldn't it. That this whole thing could be plumbed without a pump However Lisa and I being the eternal optimists will put it down to a life learning experience. The only thing is mate, is that we did seek professional advice Yes, the tanks were purchased after July 2012 however they're not actually plumbed to anything as such. We need to get the water back up the property to the toilet and washing machine. We can discuss when you come through. If I understand correctly there is a $1,500.00 rebate available until 2015??? Again, thanks for all your help with this. Things are really starting to make sense Cheers Bennie. Re: Bennie and Lisa's Landscape Project - Let the fun begin 18Apr 11, 2013 1:49 pm -Bennie- re: the trench and pergola hookup. I've decided to not hook it up until you drop past later this month. If it has to be taken apart anyway plus the increased roof area will further strain the sump pit / pump. -Bennie- What is more interesting is your comment about running the pipe directly into the lower part of the tank instead of up over the top. It never occurred to me that you could do this. Wow ! Even with the barn as well. That would be the ultimate wouldn't it. That this whole thing could be plumbed without a pump My thoughts are that the house should be gravity fed to the tank. I will reserve my judgement on the barn until I see the levels when I drop in. The diagram shows that the barn's lower roof and wall intersect is 2.5 metres high. I am assuming that the gutter's sole is possibly 100 mm below this and you need to take off another 100mm to allow for upper air entrainment in the down pipe. Take off another 300mm for head requirement and you end up with a 2 metre head. If the bottom of the tank's overflow outlet is higher than 2 metres, it means that the barn will have to either still feed to the pit or to a smaller tank fitted with the current submersible pump. Buying another tank, redoing plumbing but still using the pump anyway is obviously not a good option. If the pit wasn't there with everything plumbed to it, then the smaller tank (probably a minimum of 5,000 litres but I haven't bothered doing the sums) would be a good option as the tank would have also been a settling tank. I will have to do some rough calculations re the barn's roof area Vs pump flow with a full tank but that won't take a minute when I am on site but even if there was overflow during a major storm, the pit overflow pipe would easily cope and you won't have a flood. Re feeding through a bottom inlet, this is something that I came up with after a lot of research and it gives the following benefits.... Provided the inlet is not fitted near the very bottom of the tank, the flow rapidly dissipates inside the tank whereas flooded wet systems diverting water into the top of the tank cause significant disturbance to the sediment layer. You can also fit an easy to fit and cheap as chips DIY sediment trap along the flow path that removes a lot of the bed load. The ground level pipe is constantly flushed. The inflowing oxygen rich water oxygenates the anaerobic zone, improving the water quality. It increases the available inflow head pressure, even when the tank is full. It is very neat. It is also cheaper. I have developed two harvesting systems that use this method and I have already linked to a thread on this forum that applies to big tanks with one tank dedicated to outdoors use. I will PM you a link to the other system that also allows you to divert water to a level higher than its source - unpowered! It also allows you to feed to a big tank away from the house but also feed to a smaller tank at the house from the same pipe but it fills the smaller tank last! This automatically prioritises filling to a larger settling tank that supplies the smaller tank. Just to keep your brain ticking over, I won't PM the links until tomorrow night!!! -Bennie- Your comments re: weight vs water now makes perfect size. Thanks for the explanation. I was explaining it to my step son last night and he had a light bulb moment when he got it. You have no idea the trouble I have with plumbers! I generally use the Thomsom dam as an example. The Thomson can store over 1 trillion (1,000,000,000,000) litres of water and that is obviously a lot of weight, 1 billion tons in fact. If you could magically push a small pipe through the wall and stood in front of it, the pressure from the depth of water would blast a hole straight through you. However, if the same pipe was raised vertically so that it was above the water level and you poured 1 litre of water (weighing 1 kg) into the pipe, the additional water would immediately fall to the dam's water level...despite one billion tons of water pushing against the pipe's opening at the bottom of the dam. It is the same when you feed into a tank from a lower source...regardless of the head or the pipe size. -Bennie- Yes, the tanks were purchased after July 2012 however they're not actually plumbed to anything as such. We need to get the water back up the property to the toilet and washing machine. We can discuss when you come through. If I understand correctly there is a $1,500.00 rebate available until 2015??? I just checked and there is no longer a rebate (Victoria) unless you connect to a toilet and/or the laundry. For your tanks, you wold receive either $1,300 or $1,500. You also need a compliance certificate and the value of the goods and service must be over $750 to get one. It would mean having a tank and a pump at the house. They needn't cost much and I have a simple, quick and very cost effective method of plumbing to the cistern. http://www.water.vic.gov.au/saving/home/rebates 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: Bennie and Lisa's Landscape Project - Let the fun begin 19Apr 16, 2013 3:51 pm Hi H2O, Apologies for the delay in getting back to you...... Again the joys of life keeping me busy .... By the way, here's some shots showing you how the gutter is actually enclosed. By the way, I'd like to clarify my downpipes The round PVC down pipe you see in a couple of the pictures are not the typical downpipes we have. I only have two round ones for the pergola. ALL the other downpipes are actually the normal 100x50mm rectangular downpipes. The current state of the pipes are pretty crap to be honest. You can see some minor leakage etc.... SaveH2O My thoughts are that the house should be gravity fed to the tank. I will reserve my judgement on the barn until I see the levels when I drop in. I think you might be right there... There does seem to be just enough height to allow for an appropriate head but as you say, will be easier to see what we have when you drop in. Quote: The diagram shows that the barn's lower roof and wall intersect is 2.5 metres high. I am assuming that the gutter's sole is possibly 100 mm below this and you need to take off another 100mm to allow for upper air entrainment in the down pipe. Take off another 300mm for head requirement and you end up with a 2 metre head. If the bottom of the tank's overflow outlet is higher than 2 metres, it means that the barn will have to either still feed to the pit or to a smaller tank fitted with the current submersible pump. If we're only going to use the sump pit for the barn then I think we'll be right. Having watched the flow of water even when it was bucking down the other day the flow of the water would still be sufficient to escape from the pit when the tanks are full. However we still need to fix up the plumber's mistake of sending the tank's overflow into the sump pit. I can't believe he made such a fundamental mistake. I'm tempted to call him now to come out and fix the issue. That is send the tank's overflow into the storm water AFTER the sump pit. However before calling him I'll wait for you to come out. Quote: Buying another tank, redoing plumbing but still using the pump anyway is obviously not a good option. If the pit wasn't there with everything plumbed to it, then the smaller tank (probably a minimum of 5,000 litres but I haven't bothered doing the sums) would be a good option as the tank would have also been a settling tank. Arrrgggghhh. You're not going to believe what we did. We used to have a 5,000 litre tank but gave it to our neighbours for helping us with our garden. I simply didn't think that we'd be needing the tank and now you suggest a 5,000 litre tank... simply not far! Oh well... Such is life... No point crying about it. I do though have another smaller little tank, not sure of it's capacity though my guess is about a 1,000 litres though which is no where near enough.... Quote: Provided the inlet is not fitted near the very bottom of the tank, the flow rapidly dissipates inside the tank whereas flooded wet systems diverting water into the top of the tank cause significant disturbance to the sediment layer. This makes sense..... I'm not sure how we're going to do it with mine though since storm water is at least a mitre below the ground It's got to come up vertically at some point... Quote: I have developed two harvesting systems that use this method and I have already linked to a thread on this forum that applies to big tanks with one tank dedicated to outdoors use. I will PM you a link to the other system that also allows you to divert water to a level higher than its source - unpowered! It also allows you to feed to a big tank away from the house but also feed to a smaller tank at the house from the same pipe but it fills the smaller tank last! This automatically prioritises filling to a larger settling tank that supplies the smaller tank. Just to keep your brain ticking over, I won't PM the links until tomorrow night!!! Lol... I still need to get my head around this. Thanks for the links to the other thread and the private links. The end result is though mate that I need to work something else other than that sump pit.. Quote: I just checked and there is no longer a rebate (Victoria) unless you connect to a toilet and/or the laundry. For your tanks, you wold receive either $1,300 or $1,500. You also need a compliance certificate and the value of the goods and service must be over $750 to get one. It would mean having a tank and a pump at the house. They needn't cost much and I have a simple, quick and very cost effective method of plumbing to the cistern. Thanks for that. I'm aware of the rebate. Would be nice to utilise the 4,000+ litre tank to get the benefit of the $1,500 rebate. Plus I've already spend a $1,000 on the plumber (with receipt etc).... However the toilet / bathroom isn't hooked up. Interested to hear your idea. Thanks for all your help so far.... Cheers. bennie Re: Bennie and Lisa's Landscape Project - Let the fun begin 20Apr 16, 2013 5:08 pm ... and I'd be interested to see what you do with the soil .... I followed Fu's steps for our new garden but we have so much clay we are still having problems - I keep adding compost and trying to get the soil more friable and I used powerfeed and seasol on a regular basis to break up the clay. I am having success with most of my plants so we are getting there. I had to replace some agapanthus on the weekend as three had died - I didn't think you could kill them so I added some compost and dynamic lifter when putting the new ones in so fingers crossed .... good luck with your garden! For info on our build: viewtopic.php?f=31&t=43093 Built the McLaren by Dechellis - slab down 22 Feb - handover 30 Aug 2011 - and gardens finished 9 Dec 2012!! Ardo That is so funny! I wonder how many people know who Larry Haun is these days. I have a couple of young guys we call Mo 1 & Mo 2 who run a crew of 6 boys and… 9 15511 Thanks very much! And would the landscaper/contractor generally involve the engineer or is that something the client would do? Thanks for your help 2 10020 Landscape Design Parramatta We have been doing a large amount of landscape design work in Sydney… 0 3 |