The record California drought, now in its fourth year, is prompting fund managers to dive into the shares of water technology companies. Fund managers from T. Rowe Price, Janus, and Mairs & Power are among those that have increased their stakes in firms such as Ecolab Inc, Roper Technologies Inc and Flowserve Corp that make smart meters, efficient heaters, and software that helps restaurants, hotels and homeowners cut back on their water usage.