First off, great forum, I've certainly learned a lot just by lurking around here.
I need a bit of advice, I'm new to this whole pond building business but plan on building 2 ponds on my property.
The first should be pretty straight forward, before I bought the property they mined sand on one section which formed a nice little gully if I can call it that. From what I can tell they reached the water table and abandoned the operation. The sand is about 3' deep and then you reach clay. I haven't had it analysed yet but it doesn't crack when it dries out and it sure as hell holds water. They made a "sort-of-spillway" to try and drain it so I'm thinking just close it up and it should fill.
The second is a natural depression very close to the quarry, they had the quarry drain into this depression so it's always under about a foot of water. Because the topography is fairly flat this turned into a useless marshy area. The surrounding area also seems to drain into this depression so I'm sort of stuck with it. There is a small ditch that leads onto my neighbor's land to try and drain it but it hasn't been very effective from what I can tell.
The soil is the same clay as above.
So according to me, step one would be to dam the quarry and construct a spillway into the depression. Step two would then be to dig out the depression a bit more and build a dam all along my fence line.
Welcome to PB. Hope you find it useful and enjoyable.
How many acres are you thinking you'd cover in ponds then? How many acres of runoff area would be feeding it? The area looks green, do you get enough rainfall to keep them full?
What would you hope to do with these two ponds? Thought about what species you'd put in and from where? We don't have experience with whatever is unique to there, but be fun to learn about them.
You do the work or thinking you hire pond building? Finding a good pond guy may be tough- could start with asking folks around there who have built them recently.
Educate yourself thoroughly, it will pay off. Read read read.
Total surface area would be around 9 acres (we work in Ha though ;))
Runoff area feeding them is roughly 90 acres. We get about 27" of rain per year. And there's a spring at the top of the quarry pond.
My biggest concern is actually what to do with the spillway on the smaller pond? It'll have to drain on to my neighbors property but I'm sure we'll manage to sort something out.
Haven't really thought about fish, I'm more into it for the scenic enhancements and creating sustainable water storage. And to actually do something productive with that marshy area.
If there is sand in the area, and you don't plate the whole pond basin with clay, the water in the pond will vary in depth to the extent that the sand is completely saturated. I have a pond like that and it can vary 6' in water depth.
If you have good clay deeper, I would dig it out, layer it in 6"-8" lifts over the sand, and compact it with a multi-tired scraper or sheepsfoot roller. Do that for 4 layers until you've built up 2/3 of a meter of clay from the pond bottom all the way up past the high water line of the pond. 69cm of rain isn't a whole lot, digging the pond deeper vs. wider will help minimize evaporation.
With the spillway going to the neighbors, I don't know what the regulations are over there. What are your concerns?
My biggest concern is actually what to do with the spillway on the smaller pond? It'll have to drain on to my neighbors property but I'm sure we'll manage to sort something out.
Sounds like right now, if you would get a lot of water, it must go onto the neighbors as it is. If you dam the water up, less water should be going his way( You will need the water to keep your pond full and it will be used there, rather than sent his way.) If anything, I would think he might complain that you are cutting him off from a water source.
Thanks for the replies guys. Only the quarry area is sandy, the rest is clay, the deepest I've gone down is about 1.5m and it's all clay. Won't know for sure until we start digging but I assume the clay goes pretty deep.
The water currently runs into the adjacent property all the time due to the quarry being drained.
It can go both ways, either he can be unhappy about me cutting of his water or he can be thrilled that I'm sorting out his marshy area.
Welcome Boerseun, Looks like you have the start of a great pond(s) area on your property. I have about ten different Ideas but will not bother you with them. I do not know if you plan to keep two separate ponds but it appears they could be connected with ease with a L shaped pond in the end. As well a control channel or piping with control valves or the old school control boards to allow flow and or blocking one body of water from the other for various reasons if you want them to stay separate.
Second you may already have a idea as to one of the ponds being a brood pond to supply and or grow-out pond for the other.
You did say your main concern is the spillway, and I would say as a novice, you need to be sure the dam core if there is one extends out to or past the spillway area because you will have more water pressure in that area than before,most likely, especially if you are in a flood plane area. I cant really tell from the pictures.
The spring is great, if it flows enough to fill the one or both depressions, but it does not look like it does, so will you have to divert the flow to the ponds when they are built? Do you know the flow rate and quality of the supply water. Just as a "spring" side note if you fill over the spring it could stop the water flow permanently(not always) and or be a source of leakage if the pond covers the spring area. Water pressure from a pond can and normally does stop spring flow and can force water back into the spring channel/crack, for lack of a better term. Very similar to essup's post about fluctuating water level.
You have a great place and lot's of potential. With 27" of water you are in a simi arid area, so water supply will most likely be needed.
You may still need a significant spillway of some sort somewhere if you have flash flooding and such so you dam area is never overrun and cause a breach. Plenty of questions to be asked as well.
Thanks for the picture and please send more as you move forward in you quest for the perfect pond. You would be ahead to get Bob Lusk's books on ponds. They would give you a good foundation and use the clay just like essup said to seal your pond. Good Luck!
I'm not too worried about the rainfall, it's the middle of the dry season now and there's about a foot of water despite both the quarry and the marshy area being drained.
We're very close to the watertable and as I said there's a small spring at the top of the quarry.
