Dug Well has run dry for first time...?

I'm no expert, but wells either tap into the overall water table or they tap into an underground stream. The water table most generally will lower because of drought but can also be affected by the greater demands of more houses being built and more wells being dug. Underground streams can be affected by just about anything. Geological forces, including minuscule earthquakes, can cause the stream to change course. Other wells upstream, possibly miles away, can affect it. Municipalities tapping into aquifers can affect it. Here in the U.S., the U.S. Dept. of Agriculture has agents in every county and they can often offer helpful advice in such cirstances. Perhaps you have something similar in Canada? However, I'd say that chances are that your well needs to be deepened.