A bill aimed at tackling water-thirsty tamarisk cleared a major hurdle Tuesday, passing the U.S. House of Representatives. Tamarisk, the fluffy plant with lavender blooms, is also known as salt cedar and has invaded stream banks throughout the American West. It drinks enough water annually to supply 20 million people, according to some estimates. The Salt Cedar and Russian Olive Control Demonstration Act would provide $80 million over the next five years to assess the extent of the plants’ infestation and offer solutions. It is estimated the tamarisk plant and Russian olive trees, both of which are nonnative species, occupy...