While water demand is projected to grow by 41% by 2030, considering also the ultimate reserves of drinking water, it is believed that this element will attract the majority of investments in the coming decades. Opportunities in drinking water sector are numerous, because its process of providing and delivery of drinking water includes many aspects: management of infrastructure, design of technological solutions, conservation and water’s quality. These opportunities result from the difference between water supply and water demand; an increasingly difference that requires capital investments in production and water treatment technologies. Investments need to be combined with the knowledge on the legislation, regulatory framework and technological developments. This article may serve to clarify type of investments in drinking water sector, known by literature, to identify opportunities of investment in this sector, indicating the theoretical framework of beta and alpha risk ratio coefficient calculation and to suggest how these types of investments can be allocated to the investment portfolios.