Id love to setup a scarecrow sprinkler to keep Herons, cats and my dog
away from my pond. I dont want to have garden hose running acrosss
the yard, the pond is quite a ways away. Any easy way to use my
exisitng pump, that is feeding my waterfall, to push water to the
scarecrow? Any thoughts?

Wouldn't you have to keep the pump running all the time , so it would work
when activated by the sensor and it would probably take a fair sized pump to
spray properly ($$$$$ - both for pump and electricity)
JMO - Gale :~)