For the water sector, I've had PHO and FIW in the past, though currently only have a group of water related stocks -- BMI, ROP, TTEK, WTS, and Danaher (DHR) also has some exposure to water. See link to Water Sector below.
The expense ratios are fairly high with FIW and PHO, but they do provide the diversification aspect. Fwiw, I've been leery of the water utility and electric utility stocks in general for a few years. On the water side, their aging infrastructure is going to need major improvements going forward, which will be expensive. On the electric utility side, they are facing lots of issues going forward. After the big PG&E lawsuits, I figure it's best to use an ETF, though I'm not currently in the sector.
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