Your water utility probably publishes water quality reports annually, so look around their website as a first step. If you’re on well water, then it’s probably pretty high salinity for avocados.
If the problem is salty irrigation, then more water won’t help unless you switch water sources, like collecting rainwater and using that.
If your water is fine, then you can probably get a free or cheap soil test from your local extension office to see if your soil has high salt levels, which could be a result of soil chemistry or past fertilizer use in that location.
In that case, then Integrated Pest Management For Avocados recommends watering deeply with low salinity water, and then letting it go longer than usual between waterings to reduce the risk of root rot from overly saturated soil. I posted a photo of the relevant page on another thread with similar (albeit more severe) leaf issues: