we are have a pool installed. the area was dug out to a high bank with run off and probably 2 underground springs. there is only about 1 foot between where the pool will sit and the bank. we plan to insert a french drain to catch the water from the spring(s). what kind of retaining wall can we build in that small amount of space (1ft) all the way around the side of the pool where the bank is? Also, the top of the bank is higher than the pool will be. Is decking on top of the bank an option, even though it is higher than the pool? Any suggestions?