Drought, water diversions and other environmental pressures mean that many rivers and streams in California don’t always have enough water to support healthy fish populations and other wildlife. Environmental water transactions (EWT), a voluntary, market-based system, is one item in the toolbox of agencies and other stakeholders, which they have been using to try to increase flows in rivers and streams. And these transactions may get a boost soon as millions of dollars from the 2014 Proposition 1 water bond are assigned to projects in coming years.