smhog,

The answer depends on additional data...what is the average depth of your pond? and what is the capacity of the well?

Some numbers...an acre foot (one acre of water an average of 1 foot deep) is about 326k gallons of water...an inch of water in a one acre pond is about 27k gallons. Lets assume you have a 1/4 acre pond with an average depth of 4 feet. It would require app 326000 gallons of water to fill. Calculate your well's flow rate and you can then determine how long it will take to fill the pond. In addition, make an assumption regarding evaporation and then you can calculate what it will take to maintain the water level, in the absence of other factors such as rain water.