Design Immunity And Alternative Delivery Projects

In California, if certain statutory requirements are met, public entities can be afforded immunity from liability arising from the design of a public works project. However, public entities should be aware that the rise of alternative delivery methods may impact the availability of the design immunity defense.

Traditional Design Immunity

California’s design immunity doctrine, codified in California Government Code section 830.6 (“Section 830.6”), shields public entities from liability for injuries arising out of alleged defects in the design of water infrastructure projects — such as pipelines, pump stations, stormwater systems, flood control channels and treatment facilities — when three elements are satisfied: (1) a causal relationship exists between the approved design and the claimed injury; (2) the plans or specifications were approved in advance of construction by the entity’s governing body or an authorized employee exercising discretionary authority; and (3) substantial evidence supports the reasonableness of the design at the time of approval, even if subsequent conditions or alternative designs might appear safer in hindsight.¹ In the context of water infrastructure, this immunity extends to specific engineering features reflected in the approved plans, including hydraulic capacity, pipe alignment and materials, channel geometry, flow control structures and related safety measures. However, design immunity may be lost if the public entity becomes aware that changed physical conditions — such as increased flow demands, deformation, erosion, sedimentation, or system degradation — have rendered the design dangerous. In the event of changed conditions, the design immunity still applies for a reasonable period of time to allow the public entity to take reasonable corrective action, including providing appropriate warnings, obtaining funding for remedial work and performing such remedial work.²

Alternative Delivery Design Immunity

In an alternative delivery model, the application of design immunity is more complex due to the blending of design responsibilities between the public entity and private actors. Considering these shared responsibilities, a public entity should ensure that it retains enough involvement in the design process in its alternative delivery contracts such that it will maintain design immunity under Section 830.6.

In many alternative delivery projects, the developer is responsible for both the design and construction of the project, which can improve efficiency, minimize design defect risks for the public entity and streamline the design process. As such, making the developer responsible for both the design and construction should significantly shorten the typically lengthy design phase. While more efficient, this expedited process could lead to a sparser record regarding the design process. This result can be addressed via contract provisions requiring the submission of such records to the public agency owner. In order to maintain design immunity under Section 830.6, particularly for complex projects, a public entity should consider requiring developers to submit written design decision logs documenting alternatives considered and reasons for selection or rejection. A public entity should also consider requiring the preservation and and possible submission of turnover, interim and final design communications, calculations and models.

Another advantage of alternative delivery projects is the ability of a developer to quickly institute design changes in order to optimize efficiency during the construction phrase. In traditional models, a design change could involve a lengthy request for change order process and subsequent change order negotiations. By contrast, the developer in an alternative delivery project is less likely to seek permission for design changes or submit a change order request (or contingency payment request) for design changes, unless those changes will materially impact price, scope or schedule. As such, without contract language governing such design changes, a developer may implement a design change during the construction phase without obtaining express prior approval from the public entity owner. In those cases, the public entity may be unable to show that a public official or city engineer approved the design change in advance of construction — a showing necessary to establish the “discretionary approval” element of design immunity. Again, this result can be addressed via contract provisions requiring owner approval of any changes affecting function, safety, or performance — even those without schedule or cost impacts — that would constitute a “design change.”

In sum, to preserve design immunity, a public agency should stay meaningfully involved in the design process and preserve a record showing discretionary, reasonable approval of any design changes made throughout the course of the project. In addition, a public agency should consider contract provisions that require a developer to keep a thorough record of any design-related decisions, including rejected design features and minor design changes, even if such decisions do not require a change order. With sufficient involvement and clear recordkeeping, a public agency can preserve design immunity under Section 830.6 while benefiting from the efficiencies of alternative delivery projects.

Footnotes

1 See Stufkosky v. Dep’t of Transportation (2023) 97 Cal.App.5th 491, 496.

2 See Hampton v. County of San Diego (2015) 62 Cal.4th 340, 347.

This article appeared in California Water Views 2026

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.