Marin Housing and the Drought – Marin Environmental Housing Collaborative

Never mind the record-shattering atmospheric river that hit the Bay Area this October, Marin (like most of the western US) is still in a state of extreme drought. Despite the fact that local reservoirs are now up to 57% of capacity from a paltry 32% in early October, this is still well below the annual average of 66% at this time of year. Marin Water (MMWD), the central and south Marin water supplier, is still asking residents to conserve water.

We know that decades of exclusionary zoning and other policies favoring luxury development, along with anti-development sentiment, are major contributors to our housing crisis. While the median home price in Marin just hit $1.7 million, some 9,465 low-income renter households do not have access to affordable homes. The lack of affordable housing is one of the reasons Marin remains the most racially disparate county in California.

The affordable housing crisis is not unique to Marin. Hence, the State is stepping in with new regional housing mandates. Marin jurisdictions are required to plan for 14,000 new homes between 2023 and 2031. Thirty-four Bay Area jurisdictions appealed their RHNA numbers; 16 used the drought as a reason for their appeal.

How does this mandate square with our exceptional drought condition?

California’s urban water suppliers are required to create water management plans, updated every five years, detailing how they will meet demand under a range of water supply scenarios. State and regional housing mandates take these plans into account. MMWD’s 2020 plan states, “The District is projected to have sufficient supplies to meet projected demands in normal years, single dry years, and multiple dry years through 2045.” However, the District is now projecting that it could run out of reservoir supplies as early as next summer.

Historically, MMWD has instituted water hookup bans for 10 of the last 50 years due to drought. These moratoria have contributed to Marin’s lack of affordable housing. A water district Board can ban new water hookups during a water shortage emergency, but it must thoroughly substantiate the necessity of doing so. While NIMBY activists are eager to use the drought as a tool to block the new housing mandates, a legal ruling reiterates that water boards are prohibited from using water allocation for the purpose of implementing a “no-growth policy.” A water district Board can ban new water hookups during a water shortage emergency, but it must thoroughly substantiate the necessity of doing so.

In May, the MMWD board again considered whether it should ban new water hookups, effectively halting most new development. Affordable housing advocates and developers protested this proposal.

Will preventing residential development save enough water to outweigh the social benefits of creating new affordable homes?

Surprisingly, MMWD staff reported that annual new construction typically accounts for less than 0.1% of the District’s annual water use. This is partially because new construction, especially multi-family construction, tends to use much less water than older single-family homes, the most common form of existing residential development in Marin. This is not out of keeping with patterns across the Bay Area (see chart below). Water consumption has declined despite population growth due to conservation efforts, new appliances, and drought-efficient landscaping.

Lessx water, more people and economy — **In the Bay Area, water use has declined even as the population and economy have grown.** Changing behavior, upgrading appliances, fixing leaks and installing drought-tolerant landscaping have all contributed to a reduction in water use since the 1980s. *Source: SPUR and the Pacific Institute*

How can new development use so little water?

New construction is required to be water and energy efficient, including requirements for water-efficient fixtures and landscaping. New construction commonly utilizes non- or less-toxic green building materials; solar capacity to generate renewable energy; graywater systems for laundry-to-landscape irrigation, and rainwater catchment. Some affordable housing developers like Eden Housing have been pioneers in this area.

On average, 42% of residential water consumed in northern California—30% of all potable water in Marin–goes to landscaping. Multi-family affordable housing tends to require less water per capita than older single-family homes, partially because it has less landscaping per person. Multi-family housing provides homes for many more households in a condensed building footprint. A smaller footprint is lighter on the land, and these smaller dwellings tend to be more affordable than single family homes, even if they are not deed-restricted affordable housing.

Desnser housing, less water — **Denser housing development uses far less water per parcel.** The biggest driver of per-parcel water use is parcel size. Adopting efficient landscape standards mainly decreases water use in homes with big yards. The range of estimated water use is shown with a box plot, where the lower end of each box is the minimum value, the line that bisects the box is the median, and the upper end is the maximum value. Minimum values reflect water use in cool, noise microclimates, whale maximum reflect use in dry, hot microclimates. *Source: SPUR and the Pacific Institute*

Cutting back landscape irrigation

This summer, the MMWD Board voted to ban the use of potable water for landscaping in new developments, allowing only recycled water. This change is projected to cut the already minimal water demand necessitated by new development.

MMWD and its northern neighbor, North Marin Water District (NMWD), have both ramped up water recycling. For example, NMWD has developed the infrastructure to pipe recycled water to large scale customers, such as golf courses and car washes. In Terra Linda, Kaiser Permanente’s new Los Gamos facility is using “purple pipe” water for flushing toilets and landscape irrigation. Much of this water is supplied by the Los Gallinas Sanitary District’s recycled water production facility, which was rebuilt and expanded this year, quadrupling its production capacity. MMWD is offering recycled water to consumers who have the capacity to transport it for use in landscape irrigation and street-sweeping. Marin does not yet have the infrastructure in place to pipe recycled water to most customers.

Marin could save much more water if existing homes would cut back on landscape irrigation by utilizing water-efficient plantings and more efficient irrigation systems, including graywater, and by reducing the amount of irrigated landscaping.

What happens next?

The MMWD board will reconsider the ban on new water hookups in December. If it decides to move ahead, the Board is likely to exempt 100% affordable housing and ADUs. While this exemption would be welcome, much of the affordable housing in Marin is generated through inclusionary zoning ordinances that require developers of market rate projects to dedicate a percentage of the units to affordable housing. The MMWD is now considering a water offset program, which would require new development to offset their projected water demand by funding new conservation or supply projects. We will discuss this option further in another newsletter.

What else could we be doing?

SPUR and the Pacific Institute recently completed an in-depth study of population and water supply projections. They explored different scenarios for growth in the Bay Area, finding that a combination of conservation and construction practices could result in zero net growth in water use despite population growth of several million people over the coming decades. But to grow sustainably, existing Bay Area homes and businesses need to be much more water efficient. Any new construction should be compact development on infill sites with a high share of multifamily housing. Finally, the Bay Area needs to invest in alternative water supplies and strengthen cooperation across regions manage supplies more effectively. To find out more about their findings and recommendations, see Water for a Growing Bay Area.

The benefits of affordable housing are clear. To trade them off for negligible water savings, especially in light of unrealized water conservation gains, is short-sighted. Ultimately, a moratorium on water hookups would achieve little as far as drought goes, while perpetuating the untenable and unsustainable lack of affordable housing in Marin, damaging the local economy, and further impeding our evolution to a more racially equitable and socially just county.