More local taxes threaten to undermine California’s fledgling legal pot industry and drive consumers underground to purchase their weed.

Voters should reject proposals on the Nov. 6 ballot for new marijuana business taxes in Union City (Measure DD), Emeryville (Measure S) and unincorporated Contra Costa (Measure R),

One key argument to California voters in 2016 for legalizing marijuana was that it would help wipe out the black market by allowing consumers to buy their pot at local dispensaries.

The marijuana would be safer, taxes could help cover related law enforcement expenses, and illegal cultivation and production, along with the associated crime, would be curtailed.

The problem is that it’s apparently not working, or at least not nearly as well as promoters and state officials had forecast. Legal marijuana sales have fallen far below expectations — state tax revenues were less than half what was forecast — while illegal sales continue to flourish.

One major concern is the high level of state and local taxes, which can add as much as 40 percent to the price of legal pot. State lawmakers this year even proposed lowering the state tax. While the bill didn’t pass, it should be a wake-up call: This is no time for more local governments to start jumping on the weed-tax bandwagon.

Voters wanted a legal marijuana market. Let’s give it a chance to take root.