Metals pollution and channel disturbance associated with historical mining, land use, and water development degraded aquatic and riparian habitat along the upper Arkansas River near Leadville, Colorado. Stream restoration was conducted for an 8 km reach to improve aquatic habitat and increase trout populations. Instream structures were prescribed to stabilize streambanks, create diverse stream morphology, and provide overhead cover, refuge, spawning, and overwinter habitat for trout. At least 90% of all structures were expected to be stable and functional 3 years after implementation. The objectives of this study were to investigate structure performance by (1) evaluating the integrity and function of instream structures and (2) evaluating the change in residual pool depths (RPD). Annual surveys utilized a rapid assessment procedure to qualitatively rank integrity, erosion, and deposition at each structure (n = 137). Rankings were investigated with ordinal regression to determine if performance varied by structure type and year. Longitudinal profile surveys were conducted annually and used to estimate RPD for 86 pools. The change in RPD was investigated with repeated measures ANOVA to determine if RPD varied between structure types and changed over time. Results suggest that some structures were more prone to failure, with higher rankings observed for boulder toe, log vanes, log toe, and boulder vanes. Pool depths increased during construction, decreased following the first runoff, and then remained relatively stable in subsequent years. Understanding the performance of instream structures from this case study will help inform the design, evaluation, and expectations for future stream restoration projects.

中文翻译：

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评估科罗拉多州河流恢复项目的河内结构性能

与历史采矿、土地利用和水资源开发相关的金属污染和河道扰乱导致科罗拉多州莱德维尔附近阿肯色河上游的水生和河岸栖息地退化。对 8 公里河段进行了溪流修复，以改善水生栖息地并增加鳟鱼数量。河内结构的目的是稳定河岸，创造多样化的河流形态，并为鳟鱼提供遮盖、避难、产卵和越冬栖息地。预计至少 90% 的结构在实施 3 年后将保持稳定并发挥作用。本研究的目的是通过以下方式研究结构性能：(1) 评估河内结构的完整性和功能；(2) 评估残池深度 (RPD) 的变化。年度调查利用快速评估程序对每个结构的完整性、侵蚀和沉积进行定性排名（n  = 137）。通过序数回归对排名进行调查，以确定性能是否因结构类型和年份而异。每年进行一次纵向概况调查，并用于估计 86 个池的 RPD。通过重复测量方差分析来研究 RPD 的变化，以确定 RPD 是否因结构类型而异以及是否随时间变化。结果表明，某些结构更容易发生故障，巨石趾、原木叶片、原木趾和巨石叶片的排名较高。水池深度在施工期间增加，在第一次径流后减少，然后在随后的几年中保持相对稳定。从本案例研究中了解河内结构的性能将有助于为未来河流恢复项目的设计、评估和预期提供信息。