I have two ponds, one on each side of my driveway, one is the upper, east side pond and the other is larger of the two on the west side. The upper flows into the lower when we get heavy rain or if the pond level doesnt lower before the next rain. The two are connected with a 24" two piece culvert. What has happened over time is that water started to run under and beside the culvert erroding the dirt. It has gotten to the point now where the top ends on both sides of the culver have fallen and created large sink holes. I need to fix this ASAP, just not sure how.
So what are my options for sealing that up and making it flow down the culver? Concrete around the who thinkg with other large rocks on top? Some sort of plastic first then large gravel then large boulders? Any help would be greatly appreciated. I am going to sand bag it for tonight and see it that will hold until the water level lowers.
pictures would help. these are my guessing steps 1) i would pump both ponds down below culvert 2) remove culvert 3) regade culvert bedding 4) if available pour 4 bags of bentonite in 5' increments (1 bag every 5 ft) under culvert for it to lay on this will prevent water from going under pipe but pipe must rest on it there can be no space between culvert and bentonite 5) place culvert and use clay plug throughout tamping in place with jumpin jack 6) encase both ends with concrete
all this said assuming you have no room for anti seep collar. even if you have room to put them on bottom of pipe and sides it may be the way to go. u can weld them on if u have metal pipe if its corrugated just dont breathe the fumes. 2 or 3 of them should work
if its corrugated culvert or hdpe and u have no bentonite you can place it directly on good clay just do not pack the dirt you lay it on because u want them ridges to work down into the clay, just pack the sides good and top. any gravel or rock around the pipe may just provoke future erosion around the culvert. the bentonite works well if available place it in there dry if water makes its way to it it will swell and shut it down its just added security
i would think all the above once pumped down could be done in 4-6 hours but i c ur worry. the quick fix would be to come in 5' from both ends dig all around pipe about 2' wide and at least 6" under pipe then replace with a clay/bentonite material forming a plug then fill in the voids around the rest of the pipe as neccessary. concreting the ends if so desired. another plug in the middle 2' wide 6" under pipe would be nice. a backhoe or even better mini trackhoe and jumpin jack packer should easily get this done in 3-4 hours assumming there is suitable clay available
when installing a subdivision culvert they require 6" gravel under them and all around them to the top. but engineers plans always call for the clay plug at both ends to prevent what is happenning to you. the slightest amount of migrating water around the pipe will eventually cause the roadway to fail. hope this gives you some ideas.
doing the 2' wide plugs may be the way to go. your only digging one 2' wide ditch in the roadway at a time and forming a plug to prevent the water migration around the pipe. not sure how deep you would have to go to get at least 6" under the culvert. if its more than 4' deep you might have to get wider to allow for working room with the hand held compacter. if not this or what essup mentioned i'm not sure what would work. i would guess a 3' wide ditch 6' long and 6" under culvert would give you plenty of working room and still have room to drive to your home and i'm talking about a ditch crossways with your culvert
It's not clear what type of material the culvert is made of. If it's galvenized steel (and even if it isn't), I'm wondering if it wouldn't be a good idea to dig out a plug near the upstream end as has been mentioned before. But instead of backfilling with clay, how about filling it back in with concrete. You would need to dig the edges of the slot until you hit good material all around. You could do this pretty quickly with one of those mini-excavators. To keep water out of the slot, you'd need to either pump down the upper pond, or maybe put in some kind of coffer dam to block water flow temporarily.
If you could afford it, I'd actually recommend pouring concrete around half the tube first, and then a week later do the other side.
bills right if money is ok. u could probably even go 1' wide and dig under culvert deeper and make a anti seep collar out of the concrete. see what local concrete minimum order is and dig enuff collars to match their minimum i'd guess 1 cy per collar but just estimating
