PERMACULTURE PONDS: Why, Where & How

[Music] so there you have it the why where and how of building and designing permaculture ponds raise your hand if you love ponds i think ponds just have exceptional value in the permaculture landscape and really benefit the ecosystem and hydrology of an area now ponds can also be a total disaster and a hazard when put in the wrong place in the wrong climate and built the wrong way so make sure you watch this video all the way through so you don't build a disaster this is a really complicated design process and it can be really tricky to figure out the why where and how to build a water body so i'm going to walk you through the thought process for designing a pond and we'll start with why now some people build ponds in the permaculture landscape just to slow the water flow within the watershed and get water to seep into the ground and build the underground water table so this pond in a way is like a beaver dam where water moves through the pond but is not held tight the pond is actually meant to seep so a pond seeps water if it's not sealed or lined in some way a lot depends on the soil type and if there's enough clay content in the soil if that soil has been compacted now i saw many examples of seepage ponds hand dug in my travels in india that you can see in the footage from this linked video multiple seepage ponds placed throughout the landscape can literally recharge and rebuild the underground aquifer of a whole area now because a seepage pond has uncompacted soil the embankment itself doesn't really hold back water so it shouldn't be planned as a structural feature seepage ponds are really excellent for restoring springs that can pop up below the pond because of the moving underground water and they can actually sub irrigate crops below them so the plants are passively watered by the underground seeping pond water the next pond type we're going to look at now is specifically meant for irrigation rain-fed irrigation ponds will collect water but then that water will be emptied during the growing season to irrigate crops so irrigation ponds should be sealed as well as possible to save water and if they can't be sealed by compaction then they should be lined water from an irrigation pond will need to be distributed into an irrigation system of some sort and most commonly people use either a lock pipe going right through the dam wall or a siphon to get the water out of the pond in a controlled way now because the water is being used for watering crops then a rain-fed irrigation pond will be empty by the end of a dry season however a recreation pond wants to stay full through the warm season for swimming and other fun and it wants to have a gradual slope on all sides so people can get in and out easily and safely with a shallow end for children now another pond that wants to stay full all throughout an entire dry season is a fire fighting pond so the water in a fire fighting pond needs to be able to be released from the pond in the event of a fire to either flood some sort of fire containment line feed a fire hose or pressurized sprinklers but often in a fire the electricity goes out so a fire fighting pond needs to be able to gravity feed a firefighting system without electricity this means it has to be placed in a higher position within the landscape now i've also seen where a fire fighting pond is designed that's big enough for a fire fighting helicopter to actually land in forested areas next we're going to look at the habitat pond now a habitat pond wants to have varied depths and edges for lots of different habitat niches now it should also have natural seasonal fluctuations of the water level so different niches are available during wet and dry periods now from the permaculture perspective a lot of different yields can be built into a habitat pond and it can be integrated with the harvest of aquatic plants waterfowl and fish but for more intensive fish production we have the aquaculture pond an aquaculture pond is a more controlled environment where the inflow and the outflow of water are managed to maintain the water level and it's also designed in a way that facilitates the harvest of the species being raised now aquaculture ponds around the world are mostly found in wet lowlands where watery landscapes are transformed into managed production systems but an aquaculture pond can also be in the system as an irrigation source where all of the nutrient-filled water can be applied to crops so as you can see a lot depends on where a pond sits within the overall water system is there a continual water source to fill ponds like a spring or a creek or do they depend on rainfall the really important thing to realize is that a pond doesn't just fall into one of these categories for example you can have a recreation pond that's also a fire fighting pond because both of these uses require that water is maintained throughout the summer but you cannot have a fire fighting pond that's also an irrigation pond because the irrigation pond will be empty during the dry season as water is applied to crops so in permaculture we work to create as many uses and yields from every element so how many uses can a single pond provide i mean the design is only limited by the creativity of the designer so how many connections can you make how about a habitat pond that also seeps water and benefits the hydrology while raising ducts and providing fertilized water for irrigation the limit is your own imagination so this is a general sense of the why and now let's talk about the where [Music] so let's start by looking at where on the slope you place a pond in relation to its storage efficiency at the high point of a slope at the top of a hill water can be stored in a pond for a high supply to gravity feed the areas below but without any runoff flowing into it from anywhere on the landscape so it would need to be filled somehow from below so as big of a hole as you're able to carve out is as much water that you can store if you have the right soil type and don't hit a shallow bedrock when you dig then as you go down the slope from steeper to more gentle slopes so you can see that the ratio of the amount of soil moved versus the amount of water stored increases as you go down to the flatter part of the slope so the flatter the area the more water that can be stored for the amount of soil that's moved but at the same time the higher up in the landscape that you can store water then you have the potential to move that water down using gravity for supply of areas down below without using electricity so you need to choose the landscape positioning carefully and the truth is you'll typically find much better soils for building ponds lower down the landscape profile so the soils may make the decision for you about where to put a pond another big consideration is placing the pond in or off of the channel now this is a contour map so looking down on the land from above this is a valley where the water is flowing through and this here is an adjacent ridge so you can place a pond in the channel where the water is flowing which has its benefits and liabilities now on the plus side the area already has water flowing through and it can have a really high efficient ratio of soil moved to water stored if placed in a gentle landform but on the minus side this is where the force of water is concentrating so in flood conditions all of the force of water is flowing in this spot in the valley so the structure right the dam the water holding structure needs to be planned with a strong overflow spillway to handle large and historic level of flood events additionally many government permitting agencies in various locations don't really like in-channel ponds because they can disrupt habitat like fish movement and wetland displacement so in-general ponds are often frowned upon by regulatory agencies and off channel ponds are usually more beloved by regulators now in an off-channel pond you'd create some sort of diversion from the channel itself or from roads or surface runoff to feed water to a pond on a ridge location so a ridge location is a more stable location because it's not in the path of a flood it may require more soil movement and thus have a lower storage efficiency these are just a couple of considerations of the wear and i go much more into specific pond types and their placement within the landscape in my key line in the augmented reality sandbox series linked right here in that series we discuss the various types of ponds positioned within the landscape so check out that series and now we're going to deal with the how [Music] pond design usually starts by drawing a cross section so you'll need to figure out what your embankment looks like and where the soil will come from to build it so where is the water actually coming from again i would direct you to my series key line in the augmented reality sandbox linked to here to talk about pond positioning and water sources so once you have an idea of what you want to do you'll need to dig test pits and see what the soil composition is at different depths to see where you have enough clay content if you're creating a pond to hold water here's another great video link that shows this process right here so this hole right here is called the boro pit and its slope is typically not steeper than three to one that means three horizontal units to one vertical unit because a machine has to drive in and out to excavate and move the soil so if you're doing this by hand then you could do whatever slope you want as long as it stays stable typically the inside slope of the dam wall itself here is no steeper than two to one and the outside slope is no steeper than three to one so you can see that you need to do some geometry to make sure you have enough soil in here and enough room to build this whole structure then you can calculate how much water the pond will hold see the water level can't come all the way up to the top of the dam because when there's a strong wind then the water can actually splash over the top and degrade the structure so you need to give several feet or about one meter of free board which is the space between the top of the dam and the water level now depending on the soil type you may need to make a clay core when you build the dam and anchor that clay core into the ground with what we call a key trench this is to make sure that water doesn't seep through the dam wall and then and that the dam is actually anchored into the ground then the most typical ways that water is taken by gravity out of the pond is through a pipe that actually goes through the dam called a lock pipe or a siphon that's pressurized and goes over the dam so a lot of the world over people just use gasoline pumps stuck in the water to get the water out of the ponds so these are the bones of the ponds but how can we make this whole system more dynamic so we can do all sorts of design to create plant niches different levels put trees on the edge the dam itself can even be planted but not with trees or woody perennials because a tree's roots can work their way through the pond and create pathways for water to leak through so let's look at this pond from above because there's another super crucial piece that if it's not done right can spell disaster as we discussed before every pond needs a spillway for overflow water when the pond is full so this spillway is the place where the water overflows from the pond when it's full and the size of that spillway needs to be related to the amount of water flowing into that dam during flood events one way to do a spillway is a wide grass channel where water will flow around the dam but it's best to put what's called a trickle pipe that's a bit lower in elevation than the spillway which is a pipe that takes the normal overflow of water from the pond not during floods and pipes it down below the dam this means that most of the time the spillway itself does not have flowing water through it but remains vegetated or clad with rock and only has water flowing during high flow events when the trickle pipe is overwhelmed so the vegetation or the rock cladding protects the spillway so it doesn't erode during flood events but it's stable at that time conventionally a lot of times people just put a culvert through the dam wall for a spillway but the thing about a culvert is it has a fixed diameter and this doesn't allow for a historic level flood event that might overwhelm the culvert and blow out the dam so a wide grassed or rock clad spillway has a lot more capacity for that unexpectedly massive volume of water that you get during a flood event another type of overflow channel and the spillway is to actually have the water overflow from one pond through an on contour swale that's connected to another pond so this way these two ponds are actually connected and fill simultaneously where the swale actually extends the holding capacity of the ponds when full now another type of spillway for a pond with a connected swale is called a level sill spillway where the overflow water goes over this wide level plane so the water is spread out evenly over the sill and flows in a sheet over the edge ideally hydrating a dry ridge below wherever these overflow waters are directed to that overflow should be treated as a resource and the receiving structure should be engineered to handle flood events so this pond could also overflow gently downslope to another pond so now we have three ponds and they're all connected and their embankments here the tops of the dams can actually function as a road and a roadway can be can connect all these three ponds so these water structures become the bones of the system and then the vegetation layer is overlaid on top of this main frame structure of roadways and water collections [Music] so getting the water design established in a permaculture system creates the foundation for all the other layers and so figuring out the why where and how of a pond can be a crucial piece for your design of the whole site now i've got to say i've just barely scratched the surface here and i may have just given you enough information to be dangerous there's so much more to say about ponds that if you're going to design or build a pond it's really imperative that you do more research than what i've presented here i've placed links in the video description down below to some really good resources including darren doherty's regrearian's handbook and katie nelson's design and construction of small earth dams so good luck out there and together we can restore the hydrology and ecosystems of this beautiful world and feed ourselves at the same time so there you have it the why where and how of building and designing permaculture ponds [Music] you

Channel: Andrew Millison

Views: 1,572,882

Keywords: permaculture ponds, permaculture design, permaculture pond, permaculture earthworks, pond building, small permaculture pond, wildlife pond ideas, wildlife pond diy, permaculture pond design, permaculture pond building, permaculture pond construction, permaculture garden pond, permaculture fish pond, permaculture duck pond, wildlife pond construction, permaculture earthworks and wetland ecosystems, pond building 101, pond building diy, pond building videos, pond building tips

Id: AadLCOqalFk

Length: 19min 5sec (1145 seconds)

Published: Mon Aug 23 2021