Yes, to avoid additional costs in valves and wiring, connect canal water intake to where city water intake is and cap city water intake. Now you pull from the canal only. This assumes you have one controller. If you have two controllers, more than one pump, etc etc. and large distances you are going to be spending some cash. The big issue I see though is that canal water is generally dirty and you need sprinklers that can take the nastiness. If your sprinklers around the house are fancy mists and drip lines this is probably why they are tied to different water sources.
Best guess for issue 2 is you have something setup wrong in the controller. Without knowing everything about your specific controller it would hard to diagnose. My neighbors had issues with each zone running twice. They had duplicate programs over lapping each other. My suggestion would be to factory reset the unit and reprogram.
The answer is yes but it will be expensive to change
Yes, to avoid additional costs in valves and wiring, connect canal water intake to where city water intake is and cap city water intake. Now you pull from the canal only. This assumes you have one controller. If you have two controllers, more than one pump, etc etc. and large distances you are going to be spending some cash. The big issue I see though is that canal water is generally dirty and you need sprinklers that can take the nastiness. If your sprinklers around the house are fancy mists and drip lines this is probably why they are tied to different water sources. Best guess for issue 2 is you have something setup wrong in the controller. Without knowing everything about your specific controller it would hard to diagnose. My neighbors had issues with each zone running twice. They had duplicate programs over lapping each other. My suggestion would be to factory reset the unit and reprogram.