The bacteria in a methane biodigester comes from the intestines of cows. So 40 deg C is only a few degrees higher. Unless your average air temperature goes well above 40 degrees you won't have any problems. Cold countries are the places that can't have unheated biodigesters.

I have seriously considered this in the past. The reason I haven't done it is because when we get enough rain to make the gully run and fill the weirs, the ground is already saturated. However there is one reason I could possibly still do it, is that during massive rain events that we can get in the wet season, the soil can get waterlogged. I have lost fruit trees to waterlogging. So the agi pipes would be taking excess water out of the soil and into the weirs to minimise waterlogging. However my reading seems to show that it is difficult to have a substantial effect on the water table using just agi pipes. I would be better off using trenches. I tried one trench and it got overgrown and became a hazard.

Hay bale walls are only useful on a permanent or semi-permanent watercourse. My gully is a normally dry gully that only flows a couple of times a year.

I'm not sure you appreciate how much water the flodds pushed through people's land.

@@Mach1Greeble fair enough probably not but in his book Peter andrews says how previously all of this was captured on the land stored underground to last with the dry spells, but probably a lot to ask for one property to do

It will depend on how much and how often the gully flows. Here the gully typically only flows a couple of times a year, but when it does, it flows with decreasing amounts for a week or more. The catchment is about a kilometre long and two hundred metres wide. Our average yearly rainfall is about 650mm. There is enough water flowing to fill up ten or so weirs in the first day or two. After that the overflow goes to the river. So you could manage with substantially smaller catchment. My weirs still tend to be dry for at least 6 months of the year. They tend to empty from the top one down, as some of the seepage from each weir goes into those below it in the gully.

The tadpoles seem to eat the mossie lava.

Biomethane is just biogas that has been refined to remove maybe two thirds of the CO2 and the hydrogen sulphide. It will burn a bit hotter than the regular biogas and will be more suitable for a direct replacement for natural gas in reticulated gas systems in towns and cities. It will have a smell added so that you can smell a leak. There is no smell from burnt biogas. The liquid fertiliser output has a bit of a smell but is not an unpleasant smell. Considering the hydrogen sulphide is a bit corrosive I wouldn't use it in a complicated system like a water heater. However you can put biogas through an activated carbon bed to remove the hydrogen sulphide and my previous bought system came with this, but i didn't find it necessary and didn't want to have to keep buying the activated carbon filters. That system also came with chlorine tablets for sterilizing the liquid output, but i found it destroyed the value of it as a fertilizer. You are unlikely to produce enough biogas to have enough to spare on top of cooking use. I have to be careful to use the biogas as efficiently as possible in order for it produce all my cooktop needs. I also have an induction cooktop for when I don't have enough biogas.

Most of the fruit trees I have planted are grafted, however some are grown from seed. With the seedlings, I aim to have ten or so trees of any type so I can select those that grow best to produce the best fruit in my soil, water and climate. For the native trees, most are what we call dry rainforest trees that can handle some frost and dryer conditions than tropical rainforest trees. I am also planting butterfly host plants and rainforest vines etc. Most of these I buy in 50mm tubes and grow them on and repot them a couple of times until they are a metre or so high in a couple of years. If I plant them smaller very few survive. I found commercial potting mix not suitable as it rots down to almost nothing and can leave the roots hanging in the air in a hole. I make my own potting mix with only about 30% compost that rots down. The rest doesn't break down once planted out: charcoal, pearlite, vermiculite and about 15% soil. By the time the large pots are planted out there isn't much more rotting down of the compost to happen in the soil.

but still, what you're doing is awesome

That hasn't turned out to be the case. The grass roots go through the shade cloth and bind it to the ground. However the upstream end must not be subject to erosion by being buried in the concrete or by continuing down into deep water on the upstream side The worst that has happened in a few tiny spots is the shade cloth gets exposed.

The first weir is the best, most natural looking weir. However the problem is the materials and machinery required. The concrete weirs do the same job, can be created by one person without needing any more machinery than a hired trencher. So it's a choice between looks and practicality.

My first weir used logs, rocks and clay that I had from my building site and a backhoe to build. It works fine and is the best looking of my weirs. It was particularly good because the logs were wedged behind growing large trees However to do more like that I would need to buy the clay and I wouldn't have the braced logs. My aim is to develop a type of weir that doesn't need heavy machinery to build, so that anyone can build them relatively cheaply, just hiring a trencher for the footing. I can build the concrete weirs pretty much all on my own, with just a friend helping with the concrete pour. With my next design using plastic sheet piles I should be able to do it totally on my own, and do away with all the work making the formwork for the concrete. It should be the least labour intensive of them all and still not be expensive to build.

Three hours drive NW of Brisbane, near Kingaroy. Being well inland we get about half the annual rainfall of Brisbane.

They are basically a concrete retaining wall. So options for how they might fail would be concrete cancer where the reo rusts and expands and cracks the concrete, or the wall moves and falls over due to not being deep enough in the ground. There was some initial cracking due to concrete shrinkage but some sealant closed the worst of them. So how long will they last? Only time will tell. My next weir will be made with plastic sheet piles. The plastic is thick enough that UV won't penetrate. I would expect them to last longer than concrete. www.escpile.com/vinyl-sheet-piles?gclid=Cj0KCQjwhY-aBhCUARIsALNIC04Odr_b_O_cMAcgnxZN4ZJqMUGcM_S7N9nqXXu0oGcbNazU1WIm0-AaAhrGEALw_wcB

I am an electrical engineer. There is no way I could get significant amounts of electricity from 1 meter of head with even the sort of flow I get when the weirs are overflowing. It requires 15 or 20 metres of head with a 100mm (4 inch) pipe to get 1000 watts

@@lovingecosystems Does that mean you need more drop ? or you mean bigger pipe?

@@matthewcarr914 you really need at least 15 metres of drop plus a 100mm pipe to generate a worthwhile amount of electricity. Even with a one meter drop a 100mm pipe would drain one of my weirs in a few hours and most of the time there is zero flow in the gully to replenish it.

My next weir will be built using sheet piles. I'll dig the trench only wide enough to fit the piles so there will be a great deal less concrete and no formwork. I'll have to find the right sealant for the joins in the piles. It will have to wait for a dry season to do it though as La Nina and the existing weirs have kept the water table in the gully too high for the trench digging

@@lovingecosystems perhaps a slightly leaky weir is fine.thanks for the explanation

Lack of vegetation contributes more to climate change than concrete. If you are using concrete to increase groundwater for vegetation, you'll eventually net a carbon negative to the environment. Humans are responsible for nearly all of the deserts in the world because we've been removing groundwater and vegetation for over 10,000 years. Scientist estimate that if we regreened only 2% of the world's deserted land, we would be removing more carbon from the atmosphere than we are putting in.

Look at it from another angle. The carbon capture and water cycle restoration over decades will easily be offset. It's the use of concrete for a greater good, the benefits outweigh the impact.

Don't beavers only build on creeks and rivers with flow? My gully only flows for a total of a couple of weeks a year. ps I am in Australia and we have never had beavers or anything like them with the possible exception of the platypus which doesn't build dams etc just burrows in the banks of streams.

@@lovingecosystems As valuable as beavers are in there home ranges, never place beavers in an environment to which they are not native. Someone released beavers in Patagonia in southern Chile and Argentina and they are wreaking havoc on that ecosystem. There is a campaign to extirpate them.

For the concrete weirs they required about $1000 or more of concrete and a couple of hundred dollars of reinforcing. The formwork was up to $1000 but is reusable. Because I did the labour myself with just a friend helping with the concrete pours, there was no labour cost.

I expect to build at least five more weirs. Based on how the current weirs leak I think the best i can hope for is to have hydrated soil in the vicinity of the gully all year and from year to year. During drought years the gully may not run at all so that it could still dry out in those years. However deep rooted trees should still be able to access what should still be a water table that is a bit higher than it would otherwise have been. I am already doing the food forest thing with legumes etc. However only the trees have guards so wallabies can eat much of it and leave some fertiliser.

No because the weirs usually end up empty about half way through the dry season. The top weirs empty first and drain into lower weirs. They aren't dams, the water seeps under and around them. Making them of concrete merely slows down the process. I have built 5 weirs now. I hope that by the time I have built 10 weirs the bottom weirs will have water in them all year and I will have turned a normally dry gully into a permanent watercourse. The spot where the bottom weir will go has a natural granite wall beside it with native fig trees already planted. So maybe I will make it a lot deeper and it can be a shady swimming hole fed by clean water that has been filtered on its way down the gully. If that happens I'll consider putting in a fish ladder

I see thistles as good if sometimes painful things as I walk everywhere barefoot. They have deep roots that pull up nutrients from down deep and when they die, the roots rot and allow air and water to better penetrate the soil. Leaving roots to compost in place is nature's way of mixing compost down into the soil. Also the native bees love thistles when they are in flower.

100mm and x 125mm on the taller wall. Both with reo

Peter was my inspiration. However my area has a lot less rainfall than his property. Hence the weirs need to hold water longer.

It would in my area if it was a named creek, even if it was a dry creek bed.

I know the local council tried to prosecute Peter Andrews for breaking some council regulation that was intended to keep more water in the rivers. However I think after a fight, common sense prevailed as leaky weirs do just that.

@@lovingecosystems yep. Kyogle council and Richmond fined some blokes extraordinary sums of money . I think its a great plan and everyone should be allowed to do it. My council Tenterfield, wont allow anyone to go near the gullys with a dozer /machinery

@@Bernie5172 So the concrete weirs would be the best as there is minimal site disturbance. It's totally different to the damage a bulldozer does.

I wouldn't personally use plastic, concrete or shadesail buried in the ground but this method keeps wetlands wet, without weirs water can flow too quickly and frequently, not absorb into the soil and cause erosion, drying out and killing back the landscape.

@@chrisp.lettuce8900 beavers

@@michaelairley2015 ahh yes the Australian beaver

@@chrisp.lettuce8900 haha!. You know what. I didn't realise this video was from Australia. I was watching a few from the US.

@@michaelairley2015 haha no worries mate, Peter Andrews style of leaky Weir using sticks and straw and organic material is basically copying what beavers do in nature to help restore the land