Everything I have read, or personally experienced, concerning cement ponds in Canada suggests that no matter how well built they are, they will eventually crack. They really are not suited to our climate. It is not odd that your pond keeps cracking in the same place - the soil in that area could be wetter (and thus expand more with frost), or there could be a large stone which is trying to make its way to the surface. All possible explanations come down to the same baseline - the pressures caused by frost in that area of your pond are greater than elsewhere on the cement surface.

You may try a non-water soluable flexible caulk to seal the crack. Depending on the size of the crack and the amount of movement over the winter, this repair MAY survive another winter. However, the more severe the winter you have, the more prepared you should be for spring surprises.

The most 'permanent' solution is, however, the liner. You should also explore some of the new flexible spray-on coatings used for swimming pools - it might end up less expensive. However, to my knowledge they haven't invented anything which is left unscathed by UV and other weathering, so these solutions too have a limited life span (ie ten years or so).

Your question concerning adapting a swimming pool to a pond is an interesting one. I have come across a number of such adaptations, but have not been directly involved in one. First of all, provided the pool is still sound (holds water!), it can be adapted. Depending on the type of filtering system installed, that also may be re-usable. Both concrete and fiberglass pools can be re-painted a more realistic colour (black, dark gray, dark green, brown-green). A vinyl liner, however, can not be changed. Personally, I would find the traditional bright blue unacceptable - but it is a matter of personal taste.

However, if your lot is very small, the new "pond" may occupy too much space, and make it difficult to landscape. In other words, even with a different colour, plants and fish, it may still look like a swimming pool. You could, on the other hand, build decking over a portion to disguise the actual size of the pond, and increase the usable space in your backyard. A traditional rectangular pool also poses problems in aesthetically altering its function.

Planting will also be a challenge, especially at the deep end. There are few fresh water plants which will grow in water deeper than four feet - and most enjoy considerably less than that. You could add weighted platforms to overcome this problem. You could take a different approach and partly fill in the swimming pool to bring the soil level up to a more appropriate level and plant directly (sand, rock, a bit of heavy clay soil - never humus rich topsoil if you ever want to see clear water and have any pond filtering system survive!). Come to think of it, you could go all the way and create a bog garden which encorporates a new smaller pond area.

What ever you do, if you have a concrete pond, do not collapse it in and cover with a thin layer of soil! This senario I do have direct experience with! And my clients, who originally did it to save money, ended up spending a lot more money once they tired of plain green lawns than they would have had they (1) taken it out and started fresh, or (2) adapted it, as you are considering.

I am of two minds. One says avoid it if you don't want it. The second is : take on the challenge - really innovative designs tend to come out of very difficult physical sites. If you go the latter route, I strongly urge you to find a local garden designer to at least provide the plans for the gardens as you finally want them. You can of course do much of the work yourself, if so inclined, and over a number of years, if desired.

You might also check out these two sites The Biggs Wildlife Pond which concerns a California site which converted an above ground swimming pool to a pond amidst a wildlife area, and Rob & Laura's Pond, a Welsh site which provides pictures of how an in ground pool was adapted for koi.

Finally, a Northern Pond page .. Thanks! I recently purchased a house and the landscaping needs to be completed. I have been thinking of installing a pond, any suggestions for this frozen part of the world ??
Doreen Gordon <dogordon@sl.lakehead.ca> Sioux Lookout, on Canada

First, I had to search on the web to find out exactly where Sioux Lookout is! I had the impression it was between Thunder Bay and Winnipeg, and was delighted to find out I was sort of right! If you are not aware, you are in Canadian Growing Zone 2a. You do have it colder than we do in Ottawa (we're zone 5a), but don't despair - you live in an incredibly beautiful area of natural lakes and streams which you can easily replicate in your backyard.

After we stopped ordering (and killing) sub-tropical and tropical water garden plants, and started using the many unendangered water plants from local lakes, rivers and streams, we realized that water gardening indeed was a great (and very Canadian) hobby! Finally, some local nurseries have gotten the hint, and now offer localized water plants too.

In regards to watergardening in Canada, I do have a few suggestions: (1) do not get into cement-lined ponds (no matter how well-built, they will eventually crack); (2) use pond liners (providing you choose a dark colour, and carefully hide the exposed edges, they can look very natural); (3) dig one portion of the pond at least a foot deeper than code requires for a cement footing in your area (in Ottawa is is 3.5 feet). By doing so, you can move all your plants to the bottom of the deep end and they will over-winter with NO problems providing they are local plants! Any kind of plant exotica means bringing them inside (to a cool, not warm, watery environment), and as far as I am concerned, just too much work to make it fun! The gardener in you may disagree!

I don't know what exactly your gardening situation is - i.e, for us re-creating parts of the local forest was ideal since we live in the middle of downtown Ottawa, and have had a long fondness for wilderness trekking. You, on the other hand may have nature much closer, and therefore may want to create something much more ordered! In my own design work, I tend to nudge people towards the replication of natural environments, but that's only my own personal preference. You can easily come upon an area of the wilderness near you that is both inspiring and calming - and replicate a portion of it to be enjoyed every day.

Remember too, it is not difficult to create a micro-climate in your back yard to jump to a warmer zone. Blocking north and northwest winds with walls and tall conifers, while ensuring that your garden's southern exposure remains unblocked speeds up spring, slows down fall, and really heats up summer! Also walls built of materials like stone and brick also retain heat, and thus are the most effective (if most expensive) north/northwest protection.

Unless part of your plans is to rid yourself of the swampy area (and perhaps a few of the bugs), you are potentially in an ideal location to develop a very natural pond setting.

First of all, determine whether the area is
(1) a "swamp" - area where water collects, and in all but the wettest summers, eventually dries up. The water will be brackish, most probably smells unpleasant too!
(2) a "bog" - an area where water collects, but constantly drains and is re-supplied with fresh water, with springs or small streams being the most common sources. This area rarely dries up totally, and the water is clear (it is undergoing constant natural filtration). The water, however, may be coloured brown (peat) and have an odor (but not of rot, more like wet earth).

If you have the latter, creating a pond within the natural bog setting could be quite easy! Dig a hole wide enough to see into and find out the level of the water table in a number of areas you can imagine placing the pond. A post-hole digger is ideal (gas or manual). You're looking for the location which has the highest water table.

If you find an area where the water table is within a foot or so from the surface, you can begin designing around that area. Your options are to slope down to the water surface, and use pebbles, beach stones etc to keep down the mud, or if you need to slow down the natural drainage, heavy clay soil or plastic liner.

If the area is really a swamp, it is no different than constructing a pond in a sandy or clay soil. You will need a liner to separate the body of water from the soil itself - and in this case, you will also have to be very careful that during rains the ground water does not flow into the pond - otherwise, the brakish water of the swamp will contaminate the pond, lead to unpleasant odors, and create a fish-unfriendly environment.

In the beginning stick with local water and bog plants - they survive our winters with great reliability, while the more temperate (tempermental) ones available from nurseries and mail-order firms can be disappointing enough to turn you off water-gardening. Get some experience under your belt before you launch into the tropicals!

Have a couple of small ponds with rubber liners and one 30ft. farm pond that has started leaking. Looking for help in plugging it.

The stock pond was excavated about 20 years ago to trap spring and surface water. It is about 25-30 ft. in circumference and, if filled, would be 3-4 ft. deep at the deep end. The soil around here is primarily clay. About six years ago the dam (deep) side was cut into to lay a 6inch pvc pipe horizontal and level with the floor of the pond. On the pond side the pvc pipe was connected to an elbow which went up (a standpipe) about 2.5 ft. The idea was to prevent over flow from going over the top of the dam. Rather, the water would flow into the standpipe and run down and through the pipe to the outside of the dam. The dam hasn't filled since. Water level stays around the level of the horizontal pipe that goes through the dam. I suspect the water found a channel alongside the horizontal pipe and has been widening it ever since. The outflow at the outside end of the pipe equals the inflow of water from the springs.

My questions - 1. How do I stop the flow? 2. Am I using Bentonite correctly when I mix a plug and drop it in or should I dump it dry or should I put it in gauze to hold it together? The outflow occasionally has a gray cast to it like the Bentonite is dissolving. 3. How should I construct a spillway if the water ever makes it to the top of the dam? I considered a rubber liner but some of the springs feed from the bottom of the pond. I would appreciate any insight you might give me.
Don Arner <74401,160@compuserve.com>
Portland, OR USA

I'll preface my comments with the proviso that my experience is entirely with man-made, lined garden ponds - and so the suggestions I have are based on readings and the like, not on direct experience.

Anyway, the basic approach you took in initially laying a pipe through the dam is very similar to what is done in my area to control the level of ponds created by beavers. The attempts are often unsuccessful, since beavers respond to the sound of running water, and studiously work until the leak is plugged. If beavers are local to your area, the edible trees are plentiful, and the water running into the pond is sufficient, you might consider a natural solution - a pair of beavers! Be forewarned - they will add to the dam to bring the water level up to at least six feet!

It appears that in digging in the drainage pipe, you disturbed too much of the surrounding compacted soil in the dam itself - the only real solution I suspect is digging out the pipe and heavily compacting the soil as it is replaced. I am not sure you can compact the soil sufficiently without the aid of a some heavy machinery. Any other plugging attempts will always be progressively tested as the water level (and therefore water pressure) increases. Increasing the breath of the dam at the original point it was disturbed with additional compacted soil is also probably also a good idea.

With regards to controlling the level of the water in the future: even small dams in my local area are heavily regulated and must have a functional, professional floodgate installed if they are holding back a natural flow of water. If you have not done so already, you should be checking with your local authorities before proceeding - should the water you are holding back be suddenly released,including during a natural flood, you will most likely be held responsible (and liable) for any damages which occur downstream.

The actual circumstances you have created with the dam may allow for some simpler solutions, however - such as a reinforced spillway at the waterlevel you want to achieve. To put it simply, create an area of the dam, reinforced with marine cement to prevent erosion by the flowing water, which is lower than all the rest of the damn. Water will flow over it more or less constantly, if the the pond's water sources are greater than natural seepage and evaporation.

Seriously, though, you should be working with your local authorities to ensure you are not creating a hazard for which you will be responsible down the road. Even though the dam was created 20 years ago (when different, if any, regulations applied), once you started altering it with the pipes, it is as if you built the dam yourself.

Just about anything that can be made to hold at least 18 inches of water can be used for container watergardening. A number, however, have problems associated with them you should be aware of at the planning stage. For example, whiskey barrells can have preservatives that are harmful, metal containers can rust or put metal ions into the water, ceramic containers do not over winter well. Most problems can be solved by either coating the inner surface with a marine coating, or using a liner. It is true, therefore, that you can use an old cast iron bathtub for a fish pond - but be aware that if there are small cracks in the porcelain, the frost will begin to spall the surface, and rusting will begin. And given the white surface, you will likely want to have the recirculating pump externally mounted. On the other hand, the drain and overflow holes are already there! With both you will have to be sure to seal well to prevent leaks with a flexible external calking. You may be able to find at a plumbing store something to adapt the size of the holes to the diameter of the tubing you will be using.

From a fish point of view, there will be fewer problems if the tub is at least partially buried in the ground, or partially in the shade to keep the water temperature down. Ensuring that as much of the surface as possible is covered with aquatic plants will also reduce water heating (and algae build-up). Goldfish especially do not like warm water - it promotes a lot of diseases. Also any water feature (like a fountain) you add will increase water temperature if the water is exposed to the air and direct sunlight. Plants are a lot more tolerant in regards to water temperature. However, In general, aquatic plants like all the sunlight you can give them in order to flower well. So the two are potentially in conflict.