Water competition in overallocated rivers is often extreme, and climate change exacerbates the challenge of balancing ecosystem and societal water needs. During a severe California drought in 2013–2014, storage in a strategic reservoir dropped to critically low levels, necessitating reduced downstream discharge during Chinook salmon, Oncorhynchus tshawytscha (Walbaum), incubation and rearing. In response, stakeholders developed an adaptive management process to balance competing water needs, including reservoir storage and salmon survival. This approach incorporated decision tree models, integrating salmon life stage transitions to define potential impacts. Life stage‐specific thresholds were identified and monitored to determine management triggers and actions. Flow reduction stranded up to 12% of incubating embryos and thus was used to trigger a flow pulse. Frequency of stranded fry in redds was reduced post‐pulse. Water quality did not change but remained within the species’ tolerance. High densities, poor body condition and aggressive behaviour of stranded fry triggered a second pulse three weeks later. This pulse reduced stranding and initiated downstream migration. Prescribed flow pulses supported outmigration of a keystone species while minimising water use during a critical period. This study evaluated ecological responses to management actions intended to ameliorate stressful low flow conditions and provided a decision‐making framework that can be used when resource use conflicts arise again.

中文翻译：

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过度分配的河流的明智的水资源管理替代方案：在干旱期间将鲑鱼生命阶段的影响纳入决策树过程

过度分配的河流中的水竞争通常是极端的，气候变化加剧了平衡生态系统和社会用水需求的挑战。在2013-2014年加州严重干旱期间，战略水库的储水量降至非常低的水平，因此需要减少奇努克鲑鱼（Oncorhynchus tshawytscha）的下游排放量。（Walbaum），孵化和饲养。作为回应，利益相关者开发了一种适应性管理流程，以平衡竞争的水需求，包括水库存储和鲑鱼生存。这种方法结合了决策树模型，整合了鲑鱼生命阶段的过渡，以定义潜在的影响。确定并监控特定于生命阶段的阈值，以确定管理触发器和操作。流量减少滞留了多达12％的孵化胚胎，因此被用来触发流量脉冲。冲动后，鱼苗中滞留鱼苗的频率降低。水质没有变化，但仍在该物种的容许范围内。三周后，高密度，不良身体状况和滞留鱼苗的攻击行为触发了第二个脉冲。该脉冲减少了绞合并启动了下游迁移。规定的流量脉冲可支持关键物种的迁移，同时最大程度地减少关键时期的用水。这项研究评估了旨在减轻压力低流量条件的管理措施的生态响应，并提供了一个决策框架，当资源使用冲突再次出现时可以使用该决策框架。