Normally a stream or creek is moving enough that the DO does not get to dangerously low for fish. However part of all streams, rivers, or creeks "anatomy" is the pool area. The pool areas are slower moving and can be treated almost in the same way a pond is at least as far as wildlife is concerned. These pools will be inhabited by the same types of fish that a small pond would hold. An aeration system could be useful only for localized aeration when the water is becoming stagnant.

My firs two questions are do you own the property the pool is on? Is this a named creek by your city/county?
Also how close is electricity to the pool?