2 Ponds and a River

GregJ · Jul 14, 2003

This past weekend I made good on a promise to a neighbor for a couple of days of tractor work for them. We were originally planning on putting in a simple circular driveway. By the time I started moving dirt, the plan changed…… We were digging 2 ponds and a connecting 140 foot river. His wife got real quiet as we started tearing up his back yard, but after a few deep breathing exercises, she seems to be doing just fine (Although we are still keeping a close eye on her). So…. after owning my tractor for nearly a year, I am fairly proficient at moving dirt, but I have no experience at pond construction. I think there is a TBN member with the tagline “Experience is something you get just after you need it”. This is a case in point. So now we have a couple of good size holes in the ground and a shallow river carved between them.
Here are the specifics. The sub soil is hard clay. The top pond is roughly 20x40 in the shape of an 8 with an island in the center (see attached picture). The lower pond will be roughly 10x20 kidney shaped. The river will be lined with sand and river rock. It is 140 feet long, 4-5 feet wide,12 inches deep and winds through the yard. We do plan to line the river because there may be some sandy spots throughout the yard. There is a 30 inch drop between ponds. The plan is to have this be a closed system during the dry months, periodically topped off with tap water. Then during the wet months (approx. 9 months of the year) it will provide natural drainage for the property. There is a tight line drain from the lower pond directly to the beach. This will regulate the level of the lower pond. There will be a return pump with float switch from the lower pond to the upper pond to keep water moving. Both ponds “might” hold water because of the heavy clay. So here are the questions:
1. Should this whole project be lined?
2. What type of liner? Cost is a major consideration.
3. What capacity and type of pump should be used to keep water flowing at a reasonable rate? 30 inches of head and 140 foot run.
4. Any good ideas on filtration?

I am leaving out a lot of details, in hopes of getting some other ideas from the group. I have seen some pictures of some beautiful ponds in this forum and look forward to any suggestions about any aspect of this project that anybody might have.

Thanks,
Greg

GregJ · Jul 14, 2003

Here is a pic of the "river".

MarkV · Jul 14, 2003

Greg, I am going to bet your will have to line it to keep you water level up but that is just a guess. Clay will hold water and is what you want when you build but as I understand it you also need compaction to get the clay to the right density.

Like I said this is just a guess so I would ask the question here. www.PONDBOSS.COM These folks are more into ponds they measure in acres but have a lot of nice knowledgeable people participating.

Good luck,
MarkV

Currmudgeon · Jul 14, 2003

( a promise to a neighbor for a couple of days of tractor work)

Sounds like famous last words to me. /forums/images/graemlins/smile.gif

( 1. Should this whole project be lined?
2. What type of liner? Cost is a major consideration.
3. What capacity and type of pump should be used to keep water flowing at a reasonable rate? 30 inches of head and 140 foot run.
4. Any good ideas on filtration? )

The heavy clay you are describing should be ideal for unlined ponds. That's what we line ponds with. The devil, as always, is in the details. How deep is the clay? What's under it? Generally, clay layers are deep, and don't have holes in them, but a hole into a sand stratum can make your pond go away. /forums/images/graemlins/frown.gif

I don't suppose you want to bother with soil borings, but a backhole pit in each pond, as deep as you can go, will tell you a lot about what's under the pond. If you can;t do that, do a couple of post holes. If you punch through to a sandy layer, backfill them with puddled clay. You want two feet of solid clay with no holes to something pervious.

If you have to line, put in about two feet of the best clay that came out of the hole. Place it in six inch lifts, break up the clods and compact the hell out of it. I'd rent a vibrator compactor for that job, your tractor wheels aren't enough.

Pump design involves a lot of details. How are you going to power the pump? A house grade sewage ejector oughta be plenty big, and maybe a 1/2 horse sump pump will do the job. The latter is cheap enough to experiment with. The bigger your pipe, the less the resistance to flow. For a 1/2 horse sump pump, 2 inch PVC oughta be OK, but I've not bothered to do any calcs.

You'll probably not want to buy a big enough pump to have any serious flow in the "river." A ditch will carry a helluva lot of flow. So, I'd make the channel level, with several steps to control the water level down to the lower pond. A series of wiers will control the flow and keep the river full. I'd think of concrete block walls with maybe a six inch drop across each wall.

I'd do the filtration in the upper pond, and let gravity do the work. Install a gravel area above the pond and pump to that. Pea stone oughta be OK. When the filter finally becomes clogged, use the tractor to rip out the stone and toss it.

Be sure you know where the water is going to go when Noah's Flood happens. It will happen thirty days after you've complete the project. I'll bet a beer on that. Murphy rules. We always design drainage stuff to handle the 100-year flood. That generally just involves setting your drainage so there is a path for the water to follow when everything is full of water. No part of that path should be in your living room.

Sounds like a fun project. I've always wanted to create a formal water garden, but my land is bottomless sand, so I'm not holding my breath on this one.

GregJ · Jul 14, 2003

Currmudgeon,
Thank you for the informative post. I looked at your profile and see that you are an "Injunear", so I am absorbing your feedback with additional respect. Yes this is going to be a fun project and the photos really don't do it justice. For some reason the photos make it look like just a bunch of dirt in abstract piles. It really is more organized and precise than it looks. One big concern that I do have is that the upper pond is going to require up to 14 inches of fill on the lower rim to level it out . I have separated the topsoil from the clay subsoil and plan to use pure clay to fill that bottom side. Your suggestion of a vibrator compactor is very good. I did dig a test hole about 6 feet deep and it just kept getting harder the deeper I got, so I am hopeful. However we are in an area with veins of clay and then sand so there are no guarantees anywhere. We do have time, so I am going to recommend that we finish detailing the pond and fill it to see how long it will hold. I really like your idea about leveling the "river" and having steps, to slow the runoff. It would require moving a little more dirt, but I think we could do it. Power would be underground and available fairly close by. I think a dedicated 20 amp circuit to the ponds for the pump and some minimal lighting would work. We are planning on pulling a wire to the upper pond for possible lighting in the future. As far as handling the excess water, the overflow is a 6 inch corrugated that ties into a 10 inch someplace within 100 feet. If it overflows, it will not jeoporadize the dwelling. Thanks again.

Greg

ronjhall · Jul 15, 2003

Greg
I have a 2500 gal pond that I built last year. It was put together with a kit from a local dealer. All the components came to $1500. Know that I have spent more time looking into pond building I find that I can put the same kit together for less money.
Here is a link to a place that sells pumps. Pumpworld.net I use the pump listed with a 2” feed. This pump uses about $20 a month in electric power.
I would line the ponds with Firestone roofing material.
Use the same product for the river.
I use a skimmer-biofilter to keep the water clear. To maintain it and help control green water I added a UV light. This one item has cut my maintance time a lot. There are other ways to filter the water but this system is easy to install.
There are a lot of site about water gardens on the Internet. Do a search and you will find more sites than you have time to read.
I have attached a drawing showing the construction of a garden pond.
The easiest part of my pond project was digging it.

EddieWalker · Jul 15, 2003

Your getting some great advice!

Don't bury any of your lines until you run everything and you are one hundred percent sure it's what you want!

I liked my water fall when I built it, then after a week I realized I wanted more water. After a month it really bothered me and I had to tear up all my rocks and add another pump.

GregJ · Jul 15, 2003

RonJHall,
Thanks for the great info. Do you have any specs or more info on the Firestone roofing material. I'm not familiar with it at all. We'll definitely look into the skimmer bio-filter and UV light as well. Your attachment is great. Dumb swedes like me sometimes need pictures.

Greg

GregJ · Jul 15, 2003

EddieWalker,
You are absolutely right about the great advice. Actually I have gone to some of the pond sites and found their forums a little weak. This group has never disappointed me for the abundance of information. Seems like there is always somebody that has a great idea.
I appreciate your sage advice about burying lines. Especially now that we are thinking of leveling out some of the runs with mini steps throughout the "river". This will require very careful layout so that we don't end up constructing a river that requires the water to run uphill.

Thanks,
Greg

Currmudgeon · Jul 15, 2003

( For some reason the photos make it look like just a bunch of dirt in abstract piles.)

If you ever figure out how to take clear photos of earthmoving prtojects, teach the rest of us, eh?

( I have separated the topsoil from the clay subsoil and plan to use pure clay to fill that bottom side.)

That's good. The topsoil will not do you much good in pond building. Save it for your landscaping. I always try for 3H:1V slopes, minimum when building embankments. You may get 2:1 to work, but you can't mow it.

Be espacially careful, wityh an embankment dam, that there is someplace for the water to go should the dam break. The channel to the lower pond should do the trick, but think it out. Water will slop over the corners if it must make a tight turn. Provide a positive spillway for that storm that causes your pond to overtop. This only neds to be say 1/2 foot lower than the rest of the dam, but you should know where that water is going. I'd consider armoring that spillway with plastic turf reinforcement mat to prevent erosion.

)
I think a dedicated 20 amp circuit to the ponds for the pump and some minimal lighting would work.)

You're talking about a very small pump, then. You will have to do the weirs in the channel, or you will have a very narrow channel with wetland weeds on the banks. /forums/images/graemlins/frown.gif

( As far as handling the excess water, the overflow is a 6 inch corrugated that ties into a 10 inch someplace within 100 feet. )

That may be OK for your normal overflow. There should be an emergency overflow to handle the monster flow. This doesn't need to be elaborate, it just needs to be thought out. The emergency overflow is almost always an overland route, because piping it gets very expensive. Generally, it is something like, across the yard, across the patio, and down the driveway. Just make sure there is high ground between the water and valuable property.