Pond repair question        5/21/15 Hi Bob, <Wendell> I recently bought a property in northern Vermont, neglected for many years, with a large (1/2 acre or about 20,000 sf) bitumen asphalt pond. <Oooh, olde school> The pond should be around 7' deep but has a leak at roughly 4'6". There is a drain valve in a manhole which I tested and works fine. My plan was to drain the pond, either fully and muck it out, <How?> or enough to expose the leak cracks and then fill and seal them. <With...?> I am reluctant to fully drain it at the moment as there are many frogs and salamanders breeding - and I think one snapping turtle which I'd like to get rid of. <Yes; I would> There are many cracks around the sloped edge with organic material growing out of them. Fortunately, a metal snow shovel seems to clear off most of it. <I'd consider making a shotcrete (and color) berm... with anchored pencil rod re-bar and mesh (chicken wire likely)> What would you recommend patching it with? <Maybe more asphalt emulsion... Henry's or such... But... really... best to have the soil tested... IF you want a more permanent improvement... See WWM re liners...> My thought was to gouge out the cracks and fill with either hydro-cement or asphalt/bitumen. <Worth trying> Is there a plastic or polymer solution to this? <Not as far as I know; no> During Feb/Mar, I measured the surface ice to be 16"+, so freeze/thaw is another problem. <Yes... a few approaches to this as well... the slope and berm...> See pics attached... Many thanks, Wendell Anderson <Let's keep chatting till you're aware of your choices here. Bob Fenner>

Re: Pond repair question        5/21/15 Hi Bob, Thank you. See below. <Uhhh; a mess for others to read through> > Subject: Pond repair question > Hi Bob, > <Wendell> > I recently bought a property in northern Vermont, neglected for many years, > with a large (1/2 acre or about 20,000 sf) bitumen asphalt pond. > <Oooh, olde school> > The pond should be around 7' deep but has a leak at roughly 4'6". There is > a drain valve in a manhole which I tested and works fine. My plan was to > drain the pond, either fully and muck it out, > <How?> {was thinking to drain it fully and rake/shovel it out) <<DO look into buying or renting a trash-pump... diaphragm type if there's much in the way of larger solids... And I suspect there will be further damage from entering the pond>> > or enough to expose the leak cracks and then fill and seal them. > <With...?>(Thoroseal WaterPlug in cracks, cover in Thoroseal or bitumen driveway sealer, Henry's roof sealer?) <<NEED to know if the damaged area is expansive... i.e. if it's moving at all. If so the Thoro products won't work; nor asphaltous material if much wet, flexible.... might try a patch... of roofing material AND the Henry's... will require a few dry days to dry the pond, dry the repair>> > I am reluctant to fully drain it at the moment as there are many frogs and > salamanders breeding - and I think one snapping turtle which I'd like to > get rid of. > <Yes; I would> > There are many cracks around the sloped edge with organic material growing > out of them. Fortunately, a metal snow shovel seems to clear off most of  it. > <I'd consider making a shotcrete (and color) berm... with anchored pencil > rod re-bar and mesh (chicken wire likely)>(I think this will be Plan B - assume you mean just the top edge to below present waterline where leak is, will it adhere to the underwater area after draining enough to expose and dry it) (I walked it and there is roughly 500' of perimeter x 6'-8' of exposed berm, about 30" in elevation depth) <<Yes to over the existing edge throughout>> > What would you recommend patching it with? > <Maybe more asphalt emulsion... Henry's or such... But... really... best to > have the soil tested... IF you want a more permanent improvement... See WWM > re liners...>(I assume a 1/2 acre liner would be most costly? - Plan C perhaps) <<I'd count on a half dollar to a dollar a square foot... for the whole project... IF the soil can be mixed w/ an impervious clay... might hold, be cheap>> > My thought was to gouge out the cracks and fill with either hydro-cement or > asphalt/bitumen. > <Worth trying>(Plan A, as above with ThoroSeal plug) > Is there a plastic or polymer solution to this? > <Not as far as I know; no> > During Feb/Mar, I measured the surface ice to be 16"+, so freeze/thaw is > another problem. > <Yes... a few approaches to this as well... the slope and berm...> > See pics attached... > Many thanks, > Wendell Anderson > <Let's keep chatting till you're aware of your choices here. Bob Fenner>(Thanks again...) <<Cheers, BobF>>

Spring fed water feature       4/4/15
Hello, I've been looking everywhere online and your web sight seems to have the most diverse information and consequent knowledgeable replies that my help me with my unique situation. The following is a description of my water feature.
<Let's have it!>
I live in a hilly wooded area with natural springs popping out in every ravine. The original homeowner dammed the ravine nearest and about 30 feet higher in elevation than the house and ran a 1.5" pipe from the pond behind the dam to a waterfall and small brook he built on the back of the house.
The waterfall is 5' tall and 4' wide. It fills a small 2 foot wide "L" shaped pond 1' deep, the short leg of the "L" is in front of the waterfall and the long leg is 8'. The flow out of the "L" shaped pond overflows to a 2' wide shallow brook that continues 30' flowing gently down hill back into the ravine. These features were all constructed with natural stone laid in concrete.
<No liner underneath....>
The waterfall and the brook sides are built with rounded stones and the pond and brook floors were built with flagstone. This was all built in the 1970's. The last 2 years I've experienced severe frost heave on posts supporting an outdoor bar I built 15 years ago that is beside the water feature.
<Ohh...>
With it being spring feed, running continuously year round a leak is not obvious and being in place for over 40 years there is a tremendous amount of calcified growth, especially on the waterfall. I'm planning to install a French drain between the bar and the water feature to control the spring leakage. Ideally I'd like to install a liner but that's not practical. So I've diverted the spring flow away from the waterfall and brook and I'm jack-hammering off the calcified waterfall growth to get back to the original stone. After that I'll start looking for leaks.
<Mmm; not likely productive>
With all the above background information what will be the best method to seal the leaks and realizing that I'll never be leak free do you think the French drain concept will interrupt the sub-surface water movement to eliminate the bar structure post supports from frost heaving.
Thanks
Jeff Dieterle
Northern Indiana
<Thank you for writing; and your kind initial words. The leakage can really only be addressed in a permanent way by applying the liner.... As you'll see it is VERY hard to locate leaks about rock/concrete... and even small joints twixt them can result in huge seepage of water. I do think your diversion of water and removal of calcification is worthwhile... but almost assuredly you'll have to lay in a liner anew a replacement feature (rather than using the existing), as the current is not likely to lend itself to modification. Bob Fenner> 
Re: Spring fed water feature       4/6/15
Thanks for the quick reply. There is no liner behind the waterfall or under the brook and I realize that a liner the only way to stop leakage.
<Yes; the only assured way>
I'm not sure how I would rebuild the waterfall with the liner behind it and replicate the original design.
<Won't be original... if possible, practical, building over the existing, using it as part of the structural trough is the route to go... extending the liner as the stream>
I'm still jack-hammering the overgrowth but it appears that a single vertical row of rounded stone was laid with
concrete (instead of mortar) and tight against the block wall behind the waterfall.
<Very typical in time failing. Bob Fenner>

Water undermining concrete dam. 7/28/10
Dear crew, I have a small pond, fed by live water. The dam is 4' tall and about 12' wide. It started leaking underneath about 4 years ago. I brought out the backhoe, dug down about 2' below the base then filled it with
concrete. The soil is clay with some large rocks. the leak stopped until recently, now it's leaking underneath again. I'm reading about polymer sealers and time activated Bentonite. I can see the holes where water is going in and coming out. I'm wondering if I could pump some of this stuff in the holes or through drilled holes? Thanks for any help, Mike.
<I wouldn't trust such a repair... Is there an ag. field agency or such you can have come out for free to appraise you of your choices? IF there is a time when the pond is or can be completely empty-ied, I'd consider blending
in materials and soil to render the basin impermeable to water. Bob Fenner>
Leaking underneath a cement dam.. 9/6/07 I have a cement dam about 40 ft long and 8ft high...3' wide...a beautiful acre pond behind fed by a small stream...this summer the stream dried up and all the water leaked out gradually from underneath the cement dam somewhere....how should I go about the repair ..please advise....Mike <Mmm, w/o knowing more, I am inclined to encourage you to have a soils engineer out to test the "overburden" of the material on the bottom, look about for areas of leaking soil-wise... and possibly a structural engineer to survey the extant dam... may need substantial re-doing... Have you taken a look/see where this volume of water would likely go given a catastrophic dam failure? Bob Fenner>
Re: leaking underneath a cement dam..  9/7/07 Hi Bob...its not that big a deal as you seem it is...the spillway of the dam leads down into a major river... <Ah, good... a relief> I believe the Dam is leaking underneath in one place....Will the treatment of sodium Bentonite probably solve my problem ?? <Is a good, semi-inexpensive worthwhile try IMO/E. Do dish it in well Bob Fenner>

Problem with my large <earthen> fish pond   6/13/07 Dear sir I have a large commercial fish pond, approximately 1 acre of sandy soil. The depth is 30 feet. My problem is that the water level goes down drastically during the winter time. My pond is situated on an agricultural land. The leakage happens mostly during irrigation period. I live in Bangladesh. How do I stop the water from seeping / receding out? Please help! Regards Tanvir <Mmm, likely there is a local clay product that can be dished in (while this basin is emptied of water) that will render an impermeable layer to the bottom. Do check with your agricultural extension agent (or such) there re "Bentonite" clays. Bob Fenner>
Re: problem with my large fish pond -- 06/14/07 Thanks a million Bob Fenner, That was a great help <Ah, good> Keep up the good work at Wet Web Media Tanvir <Am trying my friend. BobF>

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>

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