Can't tell from the pics where the water is coming from? We have very similar water springs we hunt and they can have elk coming to them year round. I have watched elk very close suck water out of the smallest little pudle you can imagine. I would either dig it out with a shovel or a pick to improve on the source or if its coming out of a side hill, haul in a stick of 1" galvanized pipe with a sledge hammer and work it into the ground to get better flow. Make sure your location GPS is off going in and out of your hot spot. You don't want anybody finding this honey hole. Either put up a tree stand or a ground blind? Sit there the whole season. Do not do any calling. I believe the elk will come...... Elk need water twice a day or more depending on activity level. Good luck!