Provided that the trunk and root system are healthy, Bay Rum will rejuvenate new leaves from cut twigs/branches and will produce suckers from any large branches/trunks.

Almond, if I think I know the one you're talking about, seeds readily in the landscape and seems to have circular whorls of leaves on it's younger branches? If I'm describing it correctly, it will rejuventate even faster than the Bay Rum.

The real question to be asking is--if you are wanting to recapture a water vista, and you know these trees get to 30-40 feet, why are you keeping them? From hereforward, someone will have to prune so much to retain an unnatural height of these trees. I think you may be best served by replanting with a tree or large shrubs that will frame your view (or whatever you need in your design) that will not become so overgrown when mature that this same issue won't come up in 10 or 15 years.