You might think it a reasonable thing for the Oregon Legislature to spend $1.8 million — barely a rounding error in a general fund budget of about $18 billion — to study groundwater supplies, a vital matter for the farms and ranches that comprise the state’s largest industry, agriculture.

Gov. Kate Brown thought so — she proposed the $1.8 million figure in her budget for the two-year period that started July 1.

So did a group of legislators — some, like Brown, from the Democratic Party, and some, including Baker County’s representative, Cliff Bentz of Ontario, Republicans.

But in this case, bipartisan support, that often-touted key to legislative action, was not sufficient.

The budget that lawmakers approved before adjourning last week did not include the $1.8 million.

No surprise, then, that they also failed to pass a bill that would have allocated $8.2 million for groundwater studies.

We’re puzzled as to why lawmakers passed on the chance to get valuable information at a bargain price.

Even the smaller amount Brown included in her budget would have allowed the state Water Resources Department to conduct twice as many groundwater studies.

Rep. Ken Helm, the Beaverton Democrat who introduced the bill budgeting $8.2 million, told The Oregonian that at the state’s current pace of studying groundwater, “we won’t get a meaningful amount (of data) until the middle of this century.”

This sluggish progress could have major effects on farmers and ranchers, because the lack of detailed studies means state officials, not to mention landowners, have little way of knowing whether their current irrigation volumes are sustainable, or whether they’re rapidly emptying aquifers.

We hope legislators recognize how important this issue is when they convene next year.