Liner: to add some margin for the liner going up and over one of the rocks (lengthwise) I'm going to get a 35' x 25' liner. This is about $370 from justliners.com for a Firestone 45 mil Pondgard EPDM liner (not including shipping).

Underlay: looks like best stuff is a non-woven geotextile 60 mil. I can get two 15' x 25' sheets for about $200 from pondandgardenwholesalers.com (including shipping).

Might get an extra 8' x 10' or so liner/underlay for extra padding on the two rocks. Would an extra 1 or 2 inches of sand be helpful on the pond bottom? My soil is mostly clay (very surprising that I found these two big rocks).

Pump/Filter:

I've heard good things about Pondmaster and Savio pumps. Seems like mag-drive is best for ponds to not have to worry about oil leaking. The pond depth is about 35" to 40". Deepest part of pond is at one end, in widest section of pond. However that end is also where I want to put the waterfall (maybe 5'-6' of total head from bottom to top of waterfall). Is it bad to have the pump and waterfall at the same end? Would enough water from opposite end of pond get sucked into pump for good pond flow? I plan the pump to be a submersible so it can sit on the bottom (and thus be quiet).

Pump size: I've read that I need 0.5 to 1x the volume of pond to go thru the pump in 1 hour. That would mean I'd need a pump 2600 to 5200 gph, which is a pretty big range. Is 2600 sufficient and more would just get me more volume over the waterfall?

Filter: I saw a pond recently that had a Savio skimmer filter/pump feeding a Savio waterfall filter and waterfall weir (sp?). The guy said that setup would cost about 2 grand. It looked like the skimmer was built right into the raised pond. My pond top is level with the ground so I don't know how that skimmer thing would work unless I dug a notch in the border for it to sit (maybe I'm picturing it wrong). Or maybe the skimmer goes inside the pond but somehow elevated so the top is level with the pond top?

A friend of mine said a filter using foam type media coiled in a bucket thing would work, that seems less complicated than a skimmer.

Waterfall - build up with cinder blocks then cover up with dirt/rocks/pondliner? Is there a better way? Pre-formed waterfall?

Pond is about 15 to 20 feet away from my main breaker box so I figure I'll have an electrician come in and run wire out to the pond for two GFCI outlets. But before I do that I need to figure out which end of the pond the pump is going to go (breaker box is closer to waterfall side). I was really hoping to do solar (lots of sun in TX) but having the pump on all the time means I would need batteries and that complicates the system. Might just add enough solar panels on my roof hooked into the house supply to cover the pond usage, that would accomplish the same thing.

Thanks for any all replies to any of my questions! I'll try to post a pic of the pond hole as it looks now.

And yes the skimmer is a notch at the end of the pond.
I don't know anything about your other questions.

You really should consider a bottom drain going to one of the filters. They are very easy to install and I have never had one leak. A bottom drain means you will never have to muck out or vacuum the pond. The pond bottom will stay clean. The bottom drain gravity flows to a filter and then the water is pumped back to the pond, already cleaned. If you want to do just a single filter, you can use a Savio skimmer and run the bottom drain line up into the bottom of the skimmer. It’s not quite as good as two separate systems, but it does still work quite well. A skimmer is pretty important. It catches leaves and other surface floating items before they settle to the bottom. Savio skimmers can be used on ponds that are not raised….that’s now my pond is. You can use a large submersible pump inside the skimmer to push water to the waterfalls.

For underlayement, consider using carpet. It’s free and it works very well!

Now my biggest concern…your pond walls. While clay might seem very strong and hard, it is actually very unstable. The microscopic partials that make up clay are round. When they get damp, they slip and slide against each other. I have known of at least 4 ponds that caved after they were built. The result is not pretty. I prefer straight vertical walls that are built of concrete block. It’s not hard to do. I just dry-stack them and then fill the cores with concrete. The vertical walls make it easy to get in and out of the pond if you ever have to get in. Sloping walls are treacherous. Once they get covered with algae, getting in and out is next to impossible. At the very least, pour a cement collar around the top of the pond to hold everything in place.

If you would like to see some great pond construction threads, check Koi Shack. There are quite a number of creative pond build threads and DIY filtration.

ccoombs1/mybusyfamil6 - looks like a skimmer will work if I cut a notch in the pond to hold the skimmer shell + pump. I was hoping to not have to dig anymore but maybe this is worth it.

Not quite picturing a bottom drain. This is a filter and submersible pump sitting on the bottom of the pond? To clean it you have to pull the filter out of the pond?

Pondmaster and Savio make 6000+ gph pumps so that is an option though 2 smaller pumps may work better. Maybe a 3000+ pump for the skimmer and 2500 gph one for the waterfall?

I also have an upper pool and a lower pool separated by a wide but short water fall. The Savio Skimmer (full size) is located at the other end of the lower pool from the waterfall.

My two magdrive pumps work fine. Laguna brand 3900 waterfall pumps.

That all said, I would take ccoombs advice, no doubt. The number one problem with my pond is keeping the detritus and other junk off the bottom. In fact, you never can keep it off the bottom. The detritus is so fine that you only stir-it up if you get in to clean the pond. So my advice would be to go with the bottom drain setup but still use a skimmer box for the top floating stuff.

Thanks for the btm drn link, ccoombs; I hadn't seen that... and thanks for the explanation of the bottom drain (not for draining, necessarily) because when I first heard about BDs that what I thought for sometime!

I like the suggestions for saving money. If you can afford the time, better to make your own... esp. underlayment; I actually think old carpet (go dumpster diving at a carpet store) is superior to the underlayments I've laid hands on.

Here's another suggestion: I'd get the rock out. It would be one thing if they were in the water atop the liner, but rolling liner up over them is just taking up space. Plus, you could use those big ones to help landscape at the edge. So it occurred to me when you talked about getting an electrician to bring a circuit out to the pond that this electrician is going to have to pay someone to trench. Most places are under the National Electric Code and that means burying the cable 30" or more... they're going to want to use a trencher. If you're going to have to get a trencher in for that you could save by getting a mini-excavator (rental from any tool/equip rental shop) and have it equipped with multiple bucket sizes... most come with options. get a slender bucket for the trench work, wider bucket for the rock. If an excavator can't lift the rock it should be able to beat on it enough to crack it smaller and scoop it out... of course, you could just pay someone to remove the large rocks.

Whatever you decide make sure you have 'em mark the area for underground utilities.

I really like your setup though.

You never did say if you planned to have fish, what kind?

Is that a german sheppard!? He/She will love the pond!

My pond is larger and I have a pair of skimmers with one bio falls and a large pressurized filter to another falls. I also have a UV Light system with 2 50W bulbs. System works well, it has been a multi-season to get it all right though.

If you have not bought skimmers, go for the type with vertical brushes. I have installed 3 types so far, but I am done now that I found these units. They are MUCH easier to maintain than the types with pads.

I have lots of gold fish in my pond and I leave them in the pond year round and they do fine. And I live in North Dakota.

Have fun.

Yep - Lucky is a German Shepherd Dog, about 6 years old. I'm sure she will love the pond though I don't really want her in it. Her nails would not be good for the liner!

I'm fine with leaving the rocks in, they'll provide some shelf space if nothing else. It would take some large equipment to get them out anyway.

The bottom drain thing sounds cool. I'm a little queasy about cutting a hole in the liner though, it would have to be the exact right size and in the exact right place to not have a leak.

I would give some serious thought to getting those rocks out. You are going to have a very difficult time smoothing the liner over them. You will have large pleats and wrinkles which will be very hard to keep clean. Plus you are using a lot of volume. Why not rent a jack hammer? Or even use a hammer drill to break them up. They are limestone, right? They should break up pretty easy.