pond leaking repair

heres our problem sink hole on pond side,  wash out on creek side.  Think there is time to save it but don't want to do anything to weird.  thinking to put lots of rocks on pond side and line the hole with wool stuff and fill with clay.  What do you think.  stu

I'm a newbie here, but was just reading about this. There may be an easier solution. 
You might line the hole with some old hay, grass clippings or leaves instead of the wool.  The anaerobic breakdown turns vegetable matter into gley. Gley is the gunky layer on the bottom of most ponds and lakes that helps keep it from leaking.  Stamp the soil firm first- if you can. If you have pigs or sheep there,  they will do the job for you.  The feet/hooves compress the soil very well to make water not seep through easily.

Thanks for the suggestion we may use a combination of these.  The reason for the wool is to use throw away items (sweaters blankets etc)and assume that they will felt the motion of the water making them impermeable to the soil.  In the mean time we are looking into clay being delivered.  This is a big pond but not enormous.  thanks 

I like the idea of reusing the wool but not sure how suited it is to this purpose.  You  may just be using a totally  different repair method.  Lots of ways to approach a problem after all.
Does the pond have a plastic liner?
Plant materials decomposing in the low oxygen environment (under the water)  create the gooey layer that normally seals ponds. 
Good luck with the project.