>>1915770idunno. one time my dad rented a backhoe to fix up the driveway, and finished a day early, so I drove out the back and dug a bigass hole as deep as the backhoe could reach. it turned into a pond and over the years teemed with life. my dad got the shits with it though, especially in regards to the mosquito question, so after like 10 years I had to fill it in, by hand.
Pic related, what it looked like filled-in. Took about 4 hours with a shovel.