Fencing the horse out of the creek so they don't muck it up, if it has a barn for your horses you will need a manure bin constructed of concrete and cement on a high spot near your barn to compost the manure, which can be sold or given to gardeners. Size would be equivalent to 2 - 12' x 12' stalls. Hope this gives you some idea. go to www.hcbc.ca for more info on environmentally friendly horse keeping.
thanks i not sure there is room for a leanto shed 12x24 and a pen land is long and narrow widest
part is 30 or 40 ft wide and going narrower. cant fence creek as all rock and very steep and deep
think of two pie wedges with creek thru middle and steep mountain on both sides actually it is a ravine
as i write this i see it is really impossible no matter how much i want to make it work.