i started building this pond a few days ago and after the core test i thought it would be relatively easy. its a wildlife management pond with a 48'' riser and 20" steel tube. it will cover approximately 8 acres and contain 10,000 cubic yards in the embankment staked by the nrcs for the wildlife department. after we started the core which a 3' core was called for and is typical here by 12' wide i noticed the scraper pumping the clay at 3 ft deep. this bugged me because fat clay will only absorb 6% over optimum moisture so we dug the core on down and were about 11' deep before we got a spring sealed off. we then cored the whole dam 6' deep making sure there were no more and there wasnt. now trying to build the dam we have found 4 more all 6' or deeper running in veins about 5 to 10 ft wide with a sand gravel mixture they are using to migrate around in the pond bottom. i'm not worried about the pond leaking since i can cut through them and i know they are coming from up hill but they are making life miserable building this pond. we have got to make sure we dont get to much of this sand in the dam and the scraper is having to work its way around the wet spots. i've seen so many questions about springs in ponds i decided to post this pond being built and what we are doing to fix these problems as we encounter them. i hope it may help someone down the road. as you look at the pics notice the dirt in the core compared to the dirt on the back side and front of the dam. we are being very carefull to put clay only in the core and mixing the sand with clay on the front side and backside being more careful with the front than the back side
