Washington State’s Growth Management Act: Successes and Emerging Challenges at 35

Thirty-five years after its inception, Washington State’s Growth Management Act (GMA) stands as a significant piece of legislation credited with curbing unchecked suburban sprawl and preserving the state’s rural character. Compared to other rapidly growing states like Colorado, Washington has demonstrated a more land-efficient approach to accommodating population increases. However, as the GMA enters its fourth decade, new challenges are emerging, particularly concerning the shift of development away from incorporated cities and into unincorporated Urban Growth Areas (UGAs).

The GMA, enacted in 1990, was a direct response to fears of a “Californication” of Washington – a future defined by relentless suburban expansion. Its core objective was to create a more predictable and sustainable development pattern by requiring counties and cities to designate UGA boundaries. Intensive development was to be concentrated within these areas, while surrounding rural lands were to be protected. This framework aimed to safeguard the environment, maintain rural aesthetics, and establish clear development rules.

Comparing Growth Patterns

The effectiveness of the GMA is starkly illustrated when contrasted with Colorado’s development trajectory. Both states have experienced substantial population growth since 2000, with Washington adding approximately 2.2 million residents and Colorado 1.7 million. Yet, Washington utilised significantly less land – 263,000 acres compared to Colorado’s 310,000 acres – to house its growing population. This translates to a 50% greater density in Washington’s growth, a testament to the state’s more structured, rules-based development regime.

Washington’s success in managing growth density is attributed to its tiered system of land-use control. While allowing for local decision-making, the GMA operates within strict state-level frameworks. This is in contrast to Colorado, which largely adheres to a “local control” model. In Colorado, many “home-rule” cities possess significant autonomy over zoning, building codes, and taxation, and can expand through annexation. This fragmentation can lead to intense competition between municipalities for tax revenue, incentivising aggressive annexation of surrounding farmland and natural areas, resulting in extensive sprawl, as seen north and south of Denver.

The GMA’s Enforcement Mechanism

A key component of Washington’s GMA is the Growth Management Hearings Board (GMHB). This quasi-judicial body has the authority to adjudicate land-use disputes and enforce state GMA laws, providing a crucial check on local government actions. The GMHB has a history of overturning local decisions that contravened the GMA’s anti-sprawl objectives, including rulings against attempts at sprawl in Spokane County, Clark County, King County, and Kitsap County.

Shifting Development Patterns

Despite the GMA’s successes in containing sprawl, recent data reveals a concerning trend: a growing proportion of population growth is occurring outside of incorporated cities, within unincorporated areas, including UGAs. While the GMA mandates that UGAs must be of sufficient size and density to accommodate projected growth, the implementation has led to unintended consequences.

In the 1990s, most population growth in Washington occurred within city limits. However, this trend has reversed over subsequent decades. Between 2010 and 2025, a significant percentage of new residents in major counties moved into unincorporated areas. For instance, Pierce County saw 51% of its new residents settle outside incorporated cities, followed by Snohomish (48%), Kitsap (41%), Clark (40%), and Spokane (36%).

This shift is partly driven by the inherent incentives within the GMA framework. Counties are legally required and financially motivated to plan for future growth, often leading them to designate large tracts of undeveloped land within UGAs for development. The promise of increased sales and property tax revenue encourages counties to compete with cities for new residents and businesses, sometimes offering tax incentives and expedited development approvals.

The definition of “areas and densities sufficient to permit” within the GMA also allows counties considerable latitude in zoning. This can result in lower-density zoning within UGAs than originally intended, leading to more sprawling development patterns. For example, King County anticipates substantial population growth but has designated land at a density of only 26 people per acre. Similarly, Thurston County’s UGA is planned for just 11 people per acre, Kitsap at 12, and Pierce at 16. Lower density translates directly to a greater acreage consumed by development.

Furthermore, developers often build at densities lower than zoning requirements, particularly in “greenfield” developments. This is because land dedicated to infrastructure such as streets, parking, stormwater management, and open spaces is frequently excluded from per-unit-per-acre calculations. A recent development in Bremerton, zoned for 8-10 homes per acre, ultimately delivered fewer than three homes per acre across 130 acres. This practice exacerbates sprawl, even within designated growth areas.

Reforms and Future Considerations

The article suggests that to defend the gains made by the GMA over its first 35 years, Washington must address these evolving patterns. Travis Merrigan, cited in the source, proposes reforms aimed at preventing suburban sprawl from undermining the Act’s original intent. These reforms would likely focus on strengthening density requirements within UGAs, re-evaluating how land is allocated for development, and potentially revisiting the incentives that encourage counties to annex or develop unincorporated areas.

The challenge lies in balancing the need for housing and economic growth with the imperative to preserve rural character and environmental quality. As Washington State continues to grow, the GMA’s ability to adapt and enforce its core principles will be crucial in shaping the state’s future urban landscape.

Key facts
| Aspect | Detail |
| :———————- | :———————————————————————————- |
| Legislation | Washington State’s Growth Management Act (GMA) |
| Anniversary | 35 years |
| Key Achievement | Reduced sprawl compared to states like Colorado; preserved rural character. |
| Emerging Challenge | Development shifting to unincorporated Urban Growth Areas (UGAs), increasing sprawl. |
| Enforcement Body | Growth Management Hearings Board (GMHB) |
| Potential Reforms Focus | Strengthening density requirements, re-evaluating land allocation, adjusting incentives. |

Source: The Urbanist – The Good, the Bad, and the UGA-ly as WA Growth Management Act Turns 35 (https://www.theurbanist.org/the-good-the-bad-and-the-uga-ly-as-wa-growth-management-act-turns-35/)

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