Last week, the California Assembly voted 62-4 to allow Marin County to downgrade its share of the regional affordable housing requirements. While the vote on AB 1537 (Levine) may not seem like a big deal (even some affordable housing groups support the change), it could embolden local governments to seek more carve-outs from the state’s signature affordable housing law.

The state law at issue is the Regional Housing Needs Assessment (“RHNA” or the unpleasant sounding “REE-Na”), by which the state determines each metropolitan region’s share of the statewide housing needs. Regional entities then divvy up the total among the jurisdiction’s cities and counties. These local governments in turn have to zone for the affordable housing amounts in their general plans (called a “housing element”). Many cities comply, but in recent years about 15 percent never even bothered to have the state certify their housing elements. Either they were too understaffed to do it or they simply didn’t care — the penalties were minimal, save for the rare lawsuit.

But in 2008, the state for the first time required local governments to have a certified housing element in order to qualify for regional transportation dollars. SB 375 (Steinberg, 2008) was hailed as a smart growth savior for California, requiring regional transportation agencies to account for greenhouse gas emissions when they developed transportation spending plans. But critics rightly noted that the law contained no penalties, so regional entities had little incentive to make meaningful changes or actually implement the paper plans. In addition, the regional entities have no control over local land use decisions, meaning that the plans have no constituency to actually build smart growth projects on the ground.

Marin County: so pretty, so unaffordable.

But SB 375 contained a little-appreciated change, which was to link the regional housing needs assessment with the regional transportation plan, (the two used to be on separate tracks). Suddenly many rural or suburban/conservative communities that resisted affordable housing faced the prospect of losing out on needed infrastructure dollars. And because of the new greenhouse gas goals in the regional transportation plans, much of this affordable housing might get built adjacent to transit, with huge potential climate benefits as a result.

Predictably, conservative communities rebelled, labeling the regional entities in charge of assigning affordable housing numbers under state law as “faceless bureaucrats” mandating “stack-and-pack” low-income housing. Backed by Tea Party and libertarian elements, these groups convinced Corte Madera in Marin County to secede from its regional entity. Other local governments around the Bay Area in particular have considered following suit.

Now with this legislative carve-out in the mix, Sacramento may be sending signals to local governments that they are willing to change the state criteria for determining local allocations. In Marin’s case, the bill would allow the county to be considered “suburban” and therefore only have to zone for 20 units to the acre instead of 30. It doesn’t seem like a big change, and it in fact makes sense to delink Marin from the higher-population San Francisco county, but it could nonetheless herald the beginning of a watering down in the housing requirements in response to grassroots opposition.

To be sure, the RNHA process is not perfect. Just because a local government zones for affordable housing doesn’t mean it will get built. Without redevelopment and a permanent funding source, affordable housing developers have taken a big hit recently in the state. Plus, zoning changes don’t mean that projects get to avoid the typical planning and approval process, a steep and expensive climb in many cities and counties.

But RNHA is still an important state policy tool that ensures low-income people have greater access to housing across the state. This weakening, should it pass the senate and be signed by the governor, may not seem like a big deal. But it could be the beginning of the end of the law, and in the process it would serve to further weaken not just our statewide affordable housing goals, but our smart growth goals as well.