I am about to start excavating a silted in pond. It is about 160 ft long and 50 ft wide, currently about 10ft deep at the deepest spot which is not very much of the overall percent of the pond. Average depth right now is about 5 feet. I live in Colo. at an elevation of 7800 ft. we have temps down to -30 in Feb occasionally, usually only a few days that get to -20 overnight. The last time my pond was full during the winter, we had about 8"-10" of ice on the pond, with varying amounts of snow on it. I don't have any aeration capability at this time.
Since I'm about to excavate it, I'd like some advice about how deep to make it so that trout can make it through the winter. I've heard things about at least 11-12' or as deep as I can get for 30% of the area of my pond. What do you guys think? Thanks, your advice is always appreciated. Barbara

I believe the rule of thumb (for fish in general) is allow at least 6 feet of depth after you subtract out your ice thickness (looks like you should allow a foot for that) and whatever depth you stand to lose in a drought (where I live, they tell me that's 2 feet). This depth over 1/3 to 1/2 of the pond should be enough deep water.

You should be OK without aeration during the Winter as long as you can clear the snow off some of the ice to let sunlight in (within a day or so of snowfall - does that mean everyday on Colorado?), enabling a little photosynthesis for O2 production. I think clearing 10-20% of the surface is considered sufficient.

Wood (lives next door to Santa's workshop) is the expert for keeping trout alive under the ice; hopefully he will be able to chime in.

Barbara - You will probably get numerous opinions about this question. 8ft - 10 ft deep along the entire bottom is probably adequate IF as Theo suggests and Wood strongly testifies to, you religously remove snow from the ice esp when snow cover is greater than 3"-4" deep. This may be an unacceptable task for your situation. In that case then the rule of thumb from me is, the deeper the pond is the less likely a winter kill will occur. 20-22 ft deep is not too deep in your situation with trout.

At 2:1 down slope of the sides and in a pond 50 ft WIDE the maximum depth feasable will be 12 ft deep. Example it will take 24 linear feet of distance to dig down 12 ft deep using a slope of 2' out and one ft down. Excavating side slopes steeper than 2:1 are possible but it usually cannot be done with a bulldozer. In cases of steeper slopes than 2:1 a track hoe with a bucket will have to do the digging. If that happens the chance of the pond leaking is always a big risk. Soil types primarily determine the amount of this leakage risk from just digging a hole in the ground as compared to pond basin that is compacted with equipment driving over the sides and bottom.

PS - Have your trout been dying from winter kill or summer kill?. Are you sure your trout survive your summers? The High muck buildup on the pond bottom no doubt causes a big disolved oxygen sag or depletion in the winter. Trout will be really stressed when the dissolved oxygen drops below 5 ppm (mg/L) whereas warm water fish will easily live at 3ppm.

Thanks for the advice guys. We have lots of sunny days here during the winter, it doesn't snow all the time but when it does, it usually sticks around for awhile. I will make a point of removing any snow once I get fish back in the pond next year.
This year I did lose some trout at the peak of the summer heat, but I started aerating with my handy trash pump for 4-5 hours per day and they survived the rest of the summer even when the pond leaked down to only 5-6 ft of water. This is the first year I've had trout so I have not had any winter over experience yet. Last winter a few bass and bluegills made it through the winter, but only a few. It had about 6 ft of water in it last winter.
I've assumed that the muck on the bottom is silt from several of the big rains we had over the last 3 years, one big enough to almost take out the dam, and that filled in the upstream sedimentation galleries with 4-5 ft of rocks and sand. HEnce the need for digging it out again, and rebuilding the galleries before we get another one of these flash floods (happens about once every 10 years the locals tell me, except it's happened twice in 3 years!)
It is a narrow site, and I plan to try to compact the clay on the steepest sides with the track hoe bucket or the skid loader. I may have to slope them a little more to get that 2:1 slope. I will plan to try to get as deep as I can over 1/3 of the pond bottom, then build in some shelves and shallow gravel areas for the bass and bluegill spawning redds.
Hopefully all this starts tomorrow! Thanks again, it's so great to be able to get this kind and quality of info from your website! Barbara

Barbara,

Any way you can get some diffuser aeration going at all in winter? No power available? That would allow you a safety net. All you would need is a very small compressor and a diffuser set in 2 to 3 feet of water to keep a hole open. Even if you did super chill the water the trout don't mind vs. warmwater fish. You could get by with a small compressor as the DC22 on this page:

http://www.stoneycreekequip.com/form/air_compressor.htm

I use it on my trout pond in winter.

I'm not pusing this company as there are other compressors etc. on the market, and we do have a few folks on here that sell them and are experts on them.

I do know some people in Co use solar powered diffusers too for their trout ponds. Maybe something to look into.

We have a diffuser that would work very well with the DC pump. Please look at our web page on products for specifically the AirPodWG.

Thanks for the suggestion about a diffuser. There is no power at the pond, and I'd have to put a solar panel quite aways up the hill to get any sustained sun, and then run the wires quite a way back down to the pump. I have thought about it, but it seemed too expensive.
The track hoe started today, and looks like I may be able to get to about 15 feet deep over at least the center channel of the pond. Bedrock rules. So I'll make due with what I can get, and then if I have winterkill, I'll invest in the diffuser. Thanks all! Barbara

We northerners who have extended ice cover would appreciate it if you would come back here and keep us informed as to how well the snow removal is working to prevent winterkill in your pond situation. I think if you do not let deep snow (greater than 3"-4") cover remain on your pond for longer than 2 weeks you will have minimal problems with winter kill. When removing snow cover try to remove about 15% to 25% of the snow for light penetration through the ice to stimulate underwater plant photosynthesis. I typically remove snow in 3'-6'wide strips length wise on the pond. For your narrow pond, clear one strip along each side over water about 4'-6' deep and one strip down the middle. It will also work okay if you just clear a larger rectangular area for ice skating.

Bill gave me the same advice some time ago, prior to stocking my trout. Snow removal does work.I do not aerate during ice cover, around 200 days of it for me. I did have problems during a summer heat wave where I noticed trout near surface gasping. I installed bottom aeration shortly after that and didn't lose any fish. I think the design of my pond helped keep temps from getting too high, it's similar in size to yours, but with steep sides (excavated with large track hoe)and not much for shallow areas. I found that operating the aerator only when air temps were lower than water temps helped. I ran for about 8 hours at night or on cold cloudy days.
If you don't have power at the pond you can run airline hundreds of feet from the power source. Search the aeration topics for suggestions. I used a very small compressor 300 feet away and it worked well for my small pond during summer.

I assume you are familiar with ice conditions and safety, but it's still worth mentioning. Although I have driven vehicles on 10" of good ice, I have also seen people drop through 24" of bad or rotten ice on foot. Deep snow cover can insulate and prevent a good freeze, please be careful when clearing snow off your pond, we want you back here to report your successes.

I would also keep fish numbers on the low side to reduce b.o.d. and stop feeding when the pond is ice covered, especially without aeration.

Oh, and for Theo, air temps were 20f this morning, the fish eating birds are starting to migrate south and Santa is just about to the "G"'s. You still have time to make the good list.

" I started with nothing and still have most of it left"

There's always a first time.

Glad you added the ice safety warning. I've gone through once (into waist deep water) and that was enough.

i agree, good job wood for the reminder. easy for people to forget. down south here, i can't imagine driving a vehicle on ice!! amazes me. i don't think we know what cold really is down here!! mark