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FAQs on Pond Repair 1

Related Articles: Pond Repair WorkLiners for Ponds

Related FAQs: Water Feature Repairs 2, Water Feature Repairs 3, More specifically: Leaks/Leaking, Seepage, Earthen Pond Repairs, Waterfall Repairs, Electrical Problems, Fountain Repairs, Faux Rock Repairs, Crack Repairs... & Foundation CoatingsLiner Pond Repairs, Liners in Pond Construction

Often it's better to treat the existing, bad pond as just a hole in the ground

Aquatic Gardens

Ponds, Streams, Waterfalls & Fountains:
Volume 1. Design & Construction
Volume 2. Maintenance, Stocking, Examples

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V. 2 Print and eBook on Amazon

by Robert (Bob) Fenner

Pond Construction problems. Hello, I am Jim Garrett and a construction management major a Western Carolina University and doing an internship this summer and a problem has arisen with a pond and waterfall at a residential site development.  I have monitored the water level  and there has been a slow leak.  The pond has no liner but was constructed with a product called Klingstone 400 manufactured by Klingstone Inc. of Waynesville, N. C.  This is a polyurethane product and the landscapers were injecting under this hard surface plastic with more urethane that reacts with water and expands to fill the voids that undermined with more leakage. <Mmm, I would have used a liner... cheaper, more dependable...> We are at a point of trying to decide what to do about this situation, should we tear it out and start over with liner.  The owner would like to see a 20 year product.  Do you think this can be salvaged? <Possibly... depending on what the basin/s look like, how much "through-put" material there already is... if the plumbing can be laid in a new bottom, you might be able to treat the current construction as "just a hole"... and re-build over it with a liner...> I would greatly like to speak with you on the phone.  My home # is 828- and I leave recorder on  while at work, and my cell # is 828-.  I would gladly call you back.  This project  was started back in April 04.  We get water from a nearby river, and right now we are considering bringing water through a 2" line from a creek approximately 1500 feet for elevation and to reach the top of the water fall that would add to volume, present pump is at 135 to 140 GPM.  Owner wants more volume for more visual effect, this waterfall and pond is at the entrance near a covered bridge that was built across the river.  This is to be a grand entrance for the development in the Appalachian Mountains.  If you could help me in anyway I would sincerely appreciate it.  Thank you for you time.  Sincerely, Jim Garrett. <The pumping issue is of course a separate item... When/if you re-do the basin/s, you might want to up-size the plumbing or add another two inch ID line... to get the flow you list... I hope you have a two speed motor... can be rigged with a timer or maybe a visual switch to turn on to the higher rate for a time... save some real money in the long haul. Am out at our place in Hawaii till the end of month... but can/will e-chat with you re this project if you'd like. Bob Fenner> James Garrett

Cement pond repair Dear Mr. Fenner, I am a park ranger for the County of Orange, with responsibility of Arden-The Helena Modjeska Historic House and Gardens.  We have two ponds at the park, both are historic.  Diameter is about 14 ft, depth is about 2.5 ft. see the attached photos. <I do> One leaks, one does not.  The ponds are historic and on the grounds of a National Historic Landmark, one of just two in Orange County.  For those reasons, I want to proceed with caution and be as minimally invasive as possible. <Understood> A previous ranger emptied the pond to clean it, left it dry for a while in the hot summer sun, which I believe caused the seal on it to shrink and cause leaking.  After refilling it, it began leaking, a couple inches per week.   Once again, last January, he emptied it, left it dry for a couple of weeks, and the leaking increased.  It has now been empty since Feb.  I have no records of how it was sealed by park staff prior to 5 years ago, but I do know it was sealed. <Okay> Some people have recommended using Mulasitcoat, and of course, I have read the link you provide, suggesting Thoroseal http://www.wetwebmedia.com/PondSubWebIndex/thoroselart.htm http://wetwebmedia.com/PondSubWebIndex/concrepart.htm. Others have suggested lining it, then adding a new coat of cement over the liner.  If possible, I would like to avoid such extensive work, however I realize a quick fix is not always a long term solution. <Yes> Can you advise me in any way? with appreciation, Diane Wollenberg, Park Ranger South County Historical Facilities <It appears you have well-considered your two principal options here... In the face of fact that this basin is not leaking very badly, that it is of historical import, I would first try the coating route... following the manufacturers installation instructions to a "T". This will likely involve a thorough cleaning, possibly a bleach and/or acid washing (an action plan for this is archived on WWM), drying, mixing of the repair coating with a "mixing bar" and drill motor... and simply application with thick brushes. I do believe that due to the age and apparent massiveness of the constructs that this repair may do the job here. If not, a liner may be retrofitted as you say.    One last concern of mine is to encourage you to pressure test the plumbing lines (if any) to assure that the leak is not to be found there instead of the basin. Bob Fenner>

Concrete pond leak Hi, <Hello there> I bought a house with a Koi pond about a year ago.  This pond has been leaking and I think the problem may be getting worse.  Without turning on the pump, the water level drops 1-2 inches a day. <Yikes>   When I turned the pump on, it drops about 5 inches a day.   Someone replaced part of the pipe (the piece that exits the pond connects to the pump) already and I think it leaks even more after that.  I was told by the guy who replaced it that it was one single piece and therefore the leak can't possibly be from the new pipe. <Mmm, not so... but in almost all cases it's not hard to install a temporary plug and pressure test the line/s. You can have most any pool supply co. do this for you if you'd like> I have to hire someone else to fix the problem once and for all, but I don't know whom I can trust.  The guy I am thinking of using told me that I should just reroute/replace all the pipes and reseal the concrete. <This is one route you could go>   He also said that the pipes used should be a white PVC pipe rather than a black PVC pipe which is what's currently in place. <Mmm, the black pipe is likely ABS, not PVC... if the installer used a mix of these two plastics... or the wrong solvent on them...>   Do you agree with what he is saying? <Possibly... I would like to see a diagram, a drawing of your basin/s and the actual plumbing schematic... have you read through my old articles on pond repair posted on WetWebMedia.com?> What kind of material would you recommend for resealing/recoating the concrete basin?  Or do you have someone that you can recommend for doing the repair in San Jose, CA? Thank you very much. Y.T. Lan <I don't know of anyone in your area, but would interview folks/companies listed in your "Yellow Page" directories under "garden ponds", "water features"... Do please read here: http://www.wetwebmedia.com/PondSubWebIndex/concrepart.htm http://www.wetwebmedia.com/PondSubWebIndex/thoroselart.htm and the associated FAQs files (links in blue, at top). Study until you feel comfortable making a decision on how to go here. It may well be that using the current basin/s as a hole, applying a liner over them, with wire and concrete, laying new plumbing within this structure... is your best route for effecting a permanent repair. Bob Fenner>

Polyurethane for Concrete injection and waterproofing. Dear Sir, <Sanjay> I am a waterproofing contractor and using acrylic polymer based, epoxy based and styrene butadiene rubber based material for my work of concrete waterproofing, structural repairs, restoration and protecting concrete structures. <Have used some of these products... "between-slab" applications only... and never been happy with them. Expensive and do not wear well> But I am not satisfied with the performance of the above material because of the not satisfying results. I heard and read much about polyurethane material for above all purposes. I don't know much about polyurethane. I am interested to know about polyurethane and how it can be used for construction and concrete problem solving purposes. <Some types of jobs can work very well with polyurethanes> Your web site is very informative and interesting. At presently I have three challenging projects are in my hand. One is of polyurethane injection grouting and another is construction joints which expand and contracts because of structural design mistake of missing expansion joints in the slab at a prestigious project of science city, India and next project is of a leaking basement vault approximately 500 feet long, 20 feet wide and 10 to 25 feet various height under ground at different levels. <... I would have a manufacturer's rep. or two and structural engineers review the use, application here> Please send me brochure, technical data of all the products and method of application thereof. <Don't have any to send. My input is from years back (14 plus) and on the user side, for ornamental aquatics (ponds, fountains) only. Not human-habitable structures> I would also like you to send some samples injection grouting material and polyurethane coating for water proofing material if it is possible. I am ready to bare the cost of samples if any. <I/we have no way of testing> Kindly confirm by e-mail before sending me broacher that you can send samples or not so that I can ask for samples of the particular material I require from your product. Kindly send detailed price list and packing sizes available for each product. Waiting for your reply. Thanking you Yours truly Sanjay Bhavsar <Again, I would contact the manufacturer of the product lines you intend to use, and local structural engineers for their input. Bob Fenner>

Material recommendation for pond crack repair... Robert, I am undertaking repairing a concrete pond that has numerous cracks. It was done "professionally" less than three years ago and to say the least it is a disaster. I read you article and I am in the process of chiseling and grinding out the cracks etc. Is there one product, elastomeric (stretching) repair system, that you recommend more than the others. Secondly what type of sealer would you recommend that I apply over the repair. Thanks for your advice and time Regards Chip Brenn <There are a few elastomeric materials that can be used for such repairs... but their use is generally not recommended. Collectively they lack the "body" to fill in the commonly large and even mobile cracks encountered in most water features. Are your openings more than just hair-line in nature? Is/are the basin/s on "original grade" or are they "moving" still? Tell me the approximate dimensions, and even better, send along a pic with some referent for physical dimensions... it may well be that you'd be best going ahead with a "complete" rebuild over the existing structure... with a liner et al. as detailed on WWM. Bob Fenner>

Leaking pond Bob, Thanks for the great website.  I live in San Diego area and have a liner/cement 2500 gallon pond that has developed a slight leak.  I lose about 2" of water a day.  The weak spot in the pond is the now unused bottom drain (first pond builder only plumbed 1" pipe, so Underwater Environments retrofitted 2" pipe after the fact).   <Yikes... trouble amount of water, good retrofit.> Anyway, do you know of anyone in the San Diego area who is good at fixing leaks?  I could get in there and do it myself, but if there is a reasonably priced expert, perhaps that is a better option than trial and error. <Am not overly familiar with many of the current companies. Do give Dan or Ann a call at Aquatic Life Services (number in the phone book) and ask them who they recommend. Bob Fenner> Thanks again for your website, Gary

Spray-on Pond liner? >I have dug a pond in my yard and uncovered a tree that is hundreds of years old and all the roots are showing. I need some kind of spray on pond liner so I can fill the hole but not cover the large roots that are showing, and I need to know if you have any suggestions Thanks Byron >>Sorry, Byron. I've not seen nor heard of such a beast. Have you Googled this? The only spray-on liners of which I'm aware go into truck beds. Is there a reason why you can't layer sand onto the root system then lay down the usual rubber-type pond liner? Marina 

Water Seepage Stops Pond! >Dear crew, >>Dear Holden.  >I have a started digging a pond that is 13' by 8'.  >>Wow, all by yourself? My back couldn't let me do that! >I dug to 30" with no problems, so I proceeded to dig to 36".  >>Cool. >Then I went to bed, I came back out the next morning to find that the bottom 6" of the pond were filled with ground water.  >>Uh oh.. now there's a problem I've never seen out here! (So Cal) >What can I do to fix this? I pumped it out, but I know it will fill again.  >>That's a tough one, I think it depends on how fast it refills. >Can I just pump it out and then put the liner in and fill it fast so that the water just pushes it down?  >>That sounds like an idea that might work, but I'd consult an geological engineer or similar to know for sure. >Can I create a new bottom of concrete?  >>I wouldn't place anything permanent like that without talking to someone. How about calling a few local general contractors? >Pea gravel?  >>That could work well as a "sink" of sorts, but again, I'd strongly suggest talking to someone in your area who's likely done similar work. There may even be code issues you should be aware of because of the ground water being so high. >Any ideas are appreciated.  Thanks, Holden  >>Sorry I can't be more definitive for you, Holden, but I wouldn't feel right trying to give you an answer that would really be a guess. Marina 

Leaky Pond While Bob is Gone >Bob, >>Not Bob, Marina today. Bob is out of the country and will return on the 28th. >Thanks for the great website.  >>He's known it since it was naught but a twinkle in his eye. >I live in San Diego area and have a liner/cement 2500 gallon pond that has developed a slight leak. I lose about 2" of water a day. The weak spot in the pond is the now unused bottom drain (first pond builder only plumbed 1" pipe, so Underwater Environments retrofitted 2" pipe after the fact).  Anyway, do you know of anyone in the San Diego area who is good at fixing leaks? >>I do not, Bob might, but I thought it better to let you know that he's been gone. You might want to contact one of the local Koi societies (I'm fairly certain there's one based in the Del Mar area, north county maybe). Or, what about the folks that did the retrofit? >I could get in there and do it myself, but if there is a reasonably priced expert, perhaps that is a better option than trial and error. >>Indeed. If you can wait, I'll be placing this message back into Bob's folder just in case, or you can write back to him (may be better just to be sure). >Thanks again for your website, Gary >>Sorry I can't be of more help at this time. Marina 

Pond Cracks I had a contractor build a 2000 gallon concrete pond covered with swimming pool plaster a few months back. Although I have not circulated the pond as yet, I have been plagued with leaks through several cracks in the concrete. <What? The basin/s should not be cracked... was there any sort of reinforcing mesh/rebar set in ahead of the concrete? Please see below> I attached several epoxy injection ports and sealed the rest of the cracks with epoxy. I injected the ports today. The effort was moderately successful. Since I am worried that further cracks could develop, particularly after I stock it with goldfish and plants, I would like to coat it before I fill it up. <Something should be done, yes> Here are the choices I have uncovered: epoxies( however, these can crack) are claimed to be the longest lasting, Mulasitcoat ( latex ) covered with plaster, roof coatings( siliconized acrylic), chlorinated rubber, neoprene rubber, polyurethane, etc. I would like the simplest, lowest cost coatings. Should I use an elastomeric material? Will roof coatings work? Are they safe for fish? What about Thoroseal? Can you help? Vijay Sampath Pond Enthusiast <Can help... all of these materials can be used and be safe... but I would not advise their use here... IF the basin/s are sufficiently cracked currently to allow leakage, these coatings will not assure a good seal... they don't have enough "body" to fill in breaks that will re-occur going forward. Instead, do read through the "concrete repair" sections posted on www.WetWebMedia.com on the Pond Subweb. Bob Fenner>

Re: Pond Sealing Bob: Are you available as a consultant. I like to do projects myself, but prefer to get good advice before I mess something up. I have just water blasted my pond to clean off the old Thoroseal and have several cracks. Also, the concrete is quite rough now. I'd be happy to pay for a short visit. Curt Yaws <Do occasionally get out and about... reminds me, I've got to call the folks out at Lakeside re a water feature they're putting in... but am out of town till the end of the month and then back out soon for another week. Are the cracks "expansive"? If they're small (less than an eighth of an inch across) and old (years) you might be able to effect a repair with a non-elastic fix (e.g. cementatious materials)... if not, the liner repair route is suggested. Bob Fenner>

Concrete Pond In Philly  Ladies and Gentlemen,  We have 50 year old pond, concrete, in Philly that the top 1/2 leaks - the pond is 8 x 5 x 2. Apparently, the top half of the sides leak because the bottom, is fine. What is the best medicine to fix this problem?  Thanks, WE  <Best to treat the existing basin as a "hole" and build another liner-based pond within it. Please read re here: http://wetwebmedia.com/PondSubWebIndex/concrepart.htm   Bob Fenner>
Re: Concrete Pond In Philly
Dear Bob, Because of the size and shape, using a rubber liner within the concrete box would look a little too chintzy. Thanks. WE <I would use a/the liner with chicken or stucco wire over it... and shotcrete or hand-pack small grade (3/8 inch nominal) concrete over/within this. Coloring the material as you wish. Bob Fenner>

Waterfall Sealer Greetings, I have an old (15 yr) waterfall constructed of rock and what looks like regular masonry mortar. When built, I do not believe there is any water barrier substrate that was put behind the stone so the waterfall now leaks like a sieve. I have filled mortar gaps with several different products that reduced the leakage, but I am still losing about 20% of my pond water daily to leakage out of the system. Can you recommend a clear, preferably acrylic, stone/mortar sealer that I can paint of the surface to seal it? I have fish in my pond, so it needs to be non-toxic. Any recommendations? <Unfortunately all the clear sealers I'm aware of have no "body" or elasticity... My only real suggestion is to use the present fall structure as your "structural trough", lay a waterproof liner over this and mortar a new one over it, making sure the water discharges well-over/into the new underlying liner. It seems you're familiar with the "waterfall construction" piece archived on WetWebMedia.com, perhaps this can grant your further insight. Bob Fenner> Thanks for your help. Jon Usher

Pond Repair issues Robert: <David> I was hoping you could help me. From the web site http://www.wetwebmedia.com/PondSubWebIndex/concrepart.htm I am quoting: For repairing the more serious "moving" and "growing" hair-line cracks, one should use an elastomeric (stretching) repair system. These are most commonly polyurethane/bitumen or chlorinated-rubber based and can be applied by brush, trowel or specialized spray equipment. These materials have a high tensile strength (elasticity) and can be applied to the questionable areas alone, or better still, over the entire basin & back of fall surface. It may be necessary and/or is strongly advised that these elastomerics in turn be coated over. Read and follow the manufacturers' instructions thoroughly. I will leave off with telling you my "horror stories" regarding "advice" from counter help and "field technicians", instead to re-emphasize that you read and follow all printed materials to the letter. Can you recommend any products/sources for these materials. I have a small (4 square feet) basin that is leaking in a waterfall and my last application of Thoroseal only helped me for about a year. <Are the cracks stable or more "moving"? In such a small basin I might try first caulking the whole with Nelson's (Chlorinated) Rubber Paint (likely available from a swimming pool supplies outlet) and then, if desired for looks, resealing it with Thoroseal> Thanks, David Rains <Make sure and use their "thinner" and follow directions to a "T". Bob Fenner>

Leaky Pond  >We just put in our pond a month ago. We seem to lose 2 inches of water within 24hrs of filling it. This presents problem because it brings the water level down past where the skimmer needs it to be.  >>This is definitely a problem, not to mention wasteful.  >The liner is new and we have been tearing it apart trying to find leak. Do you have any suggestions on trying to find the leak? Someone said milk but don't understand how that is supposed to work.  >>Me either, how much milk would you use? And, would 1% be alright, or should you use whole milk? What about cream? This is all assuming that, should the leak be at the very BOTTOM of the pond, you have x-ray vision with which to see the milk or milk product leaking underneath.  >Any other suggestions for identifying the water loss?  >>I experienced something similar with our little pre-fab here at home, and what had happened was that the waterfall outlet had somehow shifted such that it was allowing water to splash enough so that it was basically emptying the pond. Other than that, I would be obliged to empty the pond, and test the liner itself, not a fun proposition. I'm a bit better at identifying air leaks (especially having a swimming pool). Marina  >Thanks, Debbie Wilkins 

Concrete gold fish pond I have asked this question to everyone I can find that knows any thing about concrete or ponds. Now I found this site so I will try you guys. Here goes : This summer I uncovered an old kidney shaped pond in my yard. It is aprox. 4' wide & 9' long. It now is about 30" deep , but appears it should be 6" to 8" deeper to be above grade. Before it was covered up who knows how many years ago, the top edge was broken off so it could be covered with dirt. The walls are made of a concrete & something mixture with 3" field stone mixed in for filler. The inside walls are nice & smooth, coated with a light gray mortar type material. My question is what is this concrete mixture? It seems years ago I heard that concrete & vermiculite where mixed sometimes to make a lighter & more workable mix. If that's true how do you go about something like this ? Any other advice on a pond of this material would be helpful! Thanks in advance .Steve from Ohio   <There are a few possibilities as to the mortar mix that you describe, however only one tried and true "re-make" possibility to ensure the water tightness of your refurbished pond. It's detailed here: http://www.wetwebmedia.com/PondSubWebIndex/concrepart.htm Skip ahead and around to the pieces on liner use/construction. Bob Fenner>

Waterfall problem Help! The design:       A little over a year ago we expanded our patio and added a retaining wall using Crab Orchard fieldstone (and other stone) with an integrated waterfall.  The lower concrete pool contains a pump which pumps water to the upper concrete pool which when full, over flows down the face of the stone and collects in the lower pool.  The pools are no more than 4 feet long by 2 feet wide by 2+feet deep. The problem:               We have noticed a loss of water volume during operation but don't notice water leaking from the horizontal (patio) or vertical (either side of the waterfall) surfaces.  Neither pool losses leaks. The suspicion:             Other than minimal amounts lost via evaporation and absorption, water may be leaking through 'imperceptible' mortar joints between the stone. <Very common>   I cannot conceive of another reason for nearly the entire loss (approximately 2 feet/day) of water. The solution:                If my suspicion is correct, then an application of a clear, waterproofing material over the surface of the stone may prevent rapid water loss.  If so, what product is recommended? <Unfortunately as far as I know there are no such clear sealants. I recommend a cementations coating (like Thoroseal tm) that can be dyed to somewhat match the rockwork... note the height of water in your falls during operation and apply this material up to that point. If there is a suspicion that the rockwork is still moving (it was built on a solid foundation I trust), you may be better off with a coating with elastomeric properties (so it can/will stretch rather than crack)> If suspicion and solution are incorrect, please provide additional advice! Thanks Bill Florida <Bob Fenner>

Liner leak Hey Crew,   I asked a question previously about a liner leak with no positive remarks or help. I found a site that has an additive for ponds, etc. They " Say" it works. Site is http:///www.seepage control.com It takes about 1 gal for 2,000 gal. and is $125 for 5 gal. Has anyone had experience, etc. with this ESS-13??? Chuck <This site doesn't come up for me, but am familiar with similar products... They're not for liner type ponds... If you can detect the actual tear/puncture in your liner you might be able to drain the system down, clean the area and anneal/melt/weld a piece of material over the break. Please use the search feature on our site: http://www.wetwebmedia.com/ (Pond Subweb) re liner construction, repair. Bob Fenner>

Pond Liner Bubble We have a 1 acre pond which was lined with a nice thick liner a while back. <Nice> In the past few days however it has developed a 25' diameter bubble in the middle (see attached picture). Any ideas on how to fix the immediate problem and prevent a future recurrence? <Yikes... I wonder as to the cause... the make-up of the gas itself... Some way needs to be devised to install a vent...like a "sideways drilling" operation... a pipe to the area directly underneath this bubble, water, liner... to allow the gas to escape... Perhaps a well-drilling co. in your area can help... If you had known of the gas problem, perhaps shaping the basin to be more conical would have prevented this condition. Good luck, and do have the gas checked... it could be something flammable. Bob Fenner> Thanks, Glenn A. Hartzog

Leaking Pond Hello, I put in a backyard pond a few months ago and have since been experiencing a leaking problem. The pond will leak water down to 3 3/4" and then stop. I have looked around the pond edge and seen nothing. I read to trying pouring milk along the edge to find the leak. . . nothing. I am now stumped. I know that there is a leak, but cant find where. The liner is 40mil EPDM rubber. Any suggestions???? <Yes... and bear with me, as this may sound strange (now). What you may well be experiencing is a capillation phenomenon here. The outer edge of the liner can "wick" out this much water by "drawing it up" out of the system due to a continuous wet surface between the outside part of the liner and the part inside/making up the pond. Do check around the edge and drain any water puddling along there, even very moist landscape should be moved away from the liner edge. Bob Fenner> Asa Kelly

Leaking Pond Liner Do you know of any product that can be sprayed or painted onto an existing pvc liner to make it water tight? The liner is only a few years old but it no longer holds water. <There are no such "miracle cures" as far as I'm aware... but most liners can be repaired pretty easily by solventing (aka "welding") a new piece/sheet of material over the cuts. Please read here: http://www.wetwebmedia.com/PondSubWebIndex/linerspdconst.htm re pond/liner construction... and the links, other files beyond. Is yours a Butyl, PVC, EPDM liner? You will need to know this, and find a compatible/matching material to anneal to it, and solvent to do so. Bob Fenner> Thanks, Fiona Casarini

Pond Leaking Yes gentlemen, I have a livestock pond on some new land I've just moved onto and am looking to find out how to fix a leaky dam on one of the ponds. The pond is just a small livestock pond by the house but we do not have livestock by the house and we were wanting to use the pond for irrigation for our garden... We've had lots of rain and the pond will fill up with a rain but will drain out through leaching within 3 to 4 days... Is there anything I can do short of dozing and rebuilding the pond?.. A local rancher mentioned raising hogs in the thing, said they would plug any leaks.. But the problem is, all the rain... As soon as it drains, we get more rain and those darn pigs would drown (grin).. I've searched the web to no avail of how to stop the livestock pond damn leakage... Any help would sure be appreciated.. Thanks... B. Beck in Wiseman Arkansas.... <what is the composition of the pond, my friend... basal clay or other?>

Earthen Pond Leak <what is the composition of the pond, my friend... basal clay or other?> I really don't the composition of the pond... It has a clay bottom, there's a lot of rock in this ground here. I came from OK where there was a lot of red clay, but this clay isn't as dark or hard but it is clay. <I'm honestly not sure of what you would specifically ask for in your part of the country, but in many areas of the states you can order "landscapers clay" dirt cheap, so to speak. It is used in said projects for many reasons... usually as an underlayment (under decorative mulch, stone/aggregate) to channel run-off. Pond-keepers buy this clay to pack and line newly constructed earthen ponds. It makes a fine seal. Indeed it is laborious, but it is also quite inexpensive. The hog idea is quite interesting and far be it from me to doubt the wisdom of a local old-timer <wink>. It juts depends on how much you like bacon, I suppose. Best regards, Anthony>

Leaking Pond I've a small pond by US standards, but nothing in the UK is as big as you can do it !  <no... worries, perhaps we have nothing so charming as a quaint English garden pool <wink>> There's an upper pond of 600/700 gallons and a lower pond for the pump with a dam/waterfall - about 9" drop - dividing the 2. Its 4 years old. The construction is heavy duty builder's polythene as a liner, with crazy paving type stone set onto that in a thick mortar bed. Unfortunately I appear to have got one end of the 'dam' slightly wrong as it leaks slowly there (4 gallons a day I reckon) - the small area of flower bedding there is meant to be a wet garden anyway so the plants are OK but the loss rate is higher than I would like. I've got 2 choices I think - the first is to build more stone into that area to take out the leaking corner, or alternatively paint the stonework in that area with some sealant. Can you comment on that - the questions are what sealants are available, and/or if I was to build in the corner, how can I do it without disturbing the pond-life (4 Koi, etc), and what would I use as a mortar. Regards and thanks Rob Graham Edinburgh, Scotland <alas, my friend... any solution that I can think of does at least require removal of the livestock for safe repair. I must admit, from what I can gather you do have a bit of a quandary. The problem is actually a limitation by the plastic liner. Even set thick, the mortared stone cannot be trusted to make a long-term seal in either of out climates (I am in Pennsylvania, USA). Even a gentle shift of the earth from freeze/thaw will crack the mortar bed in the short term (less than five years as you have noticed) and require that the liner hold its own. Unfortunately, the Polyethylene liners are somewhat brittle and not very long lived even with a sturdy underlayment. I'm afraid that I cannot offer you a long term solution short of reconstructing the pond with a thick butyl rubber liner and sturdy underlayment. Assuming that you can find the leak, flexible sealants will only work for 6 months to 2 years at best. Epoxies require that the painted/sealed vessel/substrate is perfectly still/does not shift. Quite frankly, the least expensive and least laborious solution would be to temporarily remove the livestock, drain the pond, drop a new liner in on top(!) and dress the top edge as necessary/desired. It is better than gutting the pond for reconstruction or having to repair it three times in five years more. Best regards, Anthony>

Leaking Pond <Unfortunately, the Polyethylene liners are somewhat brittle and not very long lived even with a sturdy underlayment> Oh B*****R ! Though I don't think I'm suffering from that yet as the pond is not circulating over the dam at the moment and the level has not dropped any more than I would expect from evaporation. I think that the loss is in the corner of the big stone block dam which does not overlap the lower pond - design error - the other corner is OK so if it seeps it just runs into the lower pond. I think there is seepage at the right hand end probably over the liner which is covered by the mortar and stone. ----- / \ lower pond \ / ======== dam / \ / \ upper pond One thought is that if builders damp proof course material is so prone to breaking down, how is that our houses don't get damp ? Seems a slight conflict there. <Not really. Gravity and only occasional dampness account for most of the difference here> Many thanks for replying, even if you were the messenger of bad tidings and like any good messenger carrying bad tidings should be slain ! :>) <Shades of the Khans! Watch me dance while your spear misses my feet!> Having said all that I'm still not sure how to proceed - have to think about it. Thanks, Rob <Rob, take the route of reading through the WetWebMedia.com Pond SubWeb re pond repairs... there's a range of approaches to such fixes. Bob Fenner, back soon from Australia, land of the snail pace Net connections.>

Repair Question (Liner Pond) Robert, This is Doug Carrion. I live in Los Angeles Ca. About 2 weeks ago I had some trees cut back on my property, only to find that one of the branches while trimming punctured the bottom of our Koi Pond.  <Yikes> I had just bought the house, so I am brand new to the world. It looks to me like it is a black liner of some sort. How would I know which material this pond is? <It may well be printed/embossed on the material itself (if you can pick enough of it up to take a look), or at least the name of the manufacturer... Likely a Tetra product, green on one side, black on the other... 32 mil PVC... EPDM and Butyl Rubber have definite feels, looks to them...> Also, for repairing, do I take the chance of melting the material if I choose the wrong patch? Well if you could point me in the right direction, I would greatly appreciate the help, Thanks Carrion <Cutting to a/the chase here, do have one/two "pond service companies" come out and bid on this repair... They should be able to detail your possibilities quickly. You can then decide to DIY or no. Not much chance of melting the material if choosing wrong patch technology though. As I say, check through the "Yellow Pages" here. Bob Fenner>

Pond repair advice. Dear Sir, I have a small glass fiber pond in my garden, which is let into the garden surface and to disguise the edges, a cement and natural stone layer of about four inches has been laid on top of the pond edge. A sealing agent, Uni Bond, was added to the cement to make it waterproof. The pond edge is lower at one end, where water flows over a small waterfall into a larger pond below the waterfall. Unfortunately a leak has developed at the lower end of the pond and water is getting out between the top edge of the fibre glass pond and the stone work above it, resulting in a serious loss of water when the pond filtration system is in use. <Very, very common> Having looked on your web site and found a reference to Polyurethane/Bitumen and Chlorinated-Rubber, I am wondering if either of these materials would be suitable to use to seal the leak. Some years ago I used a material called Pond Seal, which was of a bit consistency and could be applied with the use of a brush. A couple of coats of this would seal any leak. This product no longer seems to be available in this part of the country. <Any idea of its composition?... As we will likely agree, you need something with good bonding action for both types of materials (after cleaned thoroughly and dried of course), and elasticity and "thickness" to do the job...> I have used G4 previously, but the water eventually gets between the glass fibre and the G4 sealer and a leak recommences. <Yes> Perhaps you would be good enough to advise me of the correct type of material to use for the repair, the quantity sizes available and price. Yours faithfully, D S Gurd. BEM. <Yes, certainly... if this area is not very large I am inclined to suggest a silicone (100%) sealant much like those used for caulking tubs, windows (just make sure it is 100%, sans mildewcides...) and for assembling glass aquaria. These come in a few colors... and I would try to get one that matches your rock, or failing this, the black variety... in cartridges will be best, with your fingers, perhaps a putty knife to work into and about the broken/flexing area. This repair will last a few years, and is your best bet for choices in repair materials. Bob Fenner>

Aquatic Gardens

Ponds, Streams, Waterfalls & Fountains:
Volume 1. Design & Construction
Volume 2. Maintenance, Stocking, Examples

V. 1 Print and eBook on Amazon
V. 2 Print and eBook on Amazon

by Robert (Bob) Fenner
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