College of Engineering, University of Georgia, Boyd Graduate Studies Building, 200 D.W. Brooks Dr., Athens, GA, 30602.
Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO, 80523.
J Environ Qual. 2020 May;49(3):569-581. doi: 10.1002/jeq2.20047. Epub 2020 Mar 18.
Urbanization alters the delivery of water and sediment to receiving streams, often leading to channel erosion and enlargement, which increases loading of sediment and nutrients, degrades habitat, and harms sensitive biota. Stormwater control measures (SCMs) are constructed in an attempt to mitigate some of these effects. In addition, stream restoration practices such as bank stabilization are increasingly promoted as a means of improving water quality by reducing downstream sediment and pollutant loading. Each unique combination of SCMs and stream restoration practices results in a novel hydrologic regime and set of geomorphic characteristics that interact to determine stream condition, but in practice, implementation is rarely coordinated due to funding and other constraints. In this study, we examine links between watershed-scale implementation of SCMs and stream restoration in Big Dry Creek, a suburban watershed in the Front Range of northern Colorado. We combine continuous hydrologic model simulations of watershed-scale response to SCM design scenarios with channel evolution modeling to examine interactions between stormwater management and stream restoration strategies for reducing loading of sediment and adsorbed phosphorus from channel erosion. Modeling results indicate that integrated design of SCMs and stream restoration interventions can result in synergistic reductions in pollutant loading. Not only do piecemeal and disunited approaches to stormwater management and stream restoration miss these synergistic benefits, they make restoration projects more prone to failure, wasting valuable resources for pollutant reduction. We conclude with a set of recommendations for integrated planning of SCMs and stream restoration to simultaneously achieve water quality and channel protection goals.
城市化改变了水流和泥沙输送到受纳溪流的方式，常常导致河道侵蚀和扩张，从而增加了泥沙和养分的负荷，破坏了栖息地，并危害了敏感的生物群。为了减轻这些影响，人们建造了雨水控制措施（SCMs）。此外，河道恢复实践，如河岸稳定，也越来越多地被推广，作为减少下游泥沙和污染物负荷、改善水质的一种手段。SCMs 和河道恢复实践的每种独特组合都会导致新的水文状况和一组地貌特征，这些特征相互作用决定了河道的状况，但在实践中，由于资金和其他限制，实施很少协调。在这项研究中，我们研究了科罗拉多州北部 Front Range 郊区流域大旱溪流域尺度实施 SCMs 和河道恢复之间的联系。我们结合了流域尺度对 SCM 设计方案的连续水文模型模拟和河道演变模型，以研究雨水管理和河道恢复策略在减少因河道侵蚀而产生的泥沙和吸附磷负荷方面的相互作用。模型结果表明，SCMs 和河道恢复干预措施的综合设计可以协同减少污染物的负荷。雨水管理和河道恢复的零碎和不统一的方法不仅错失了这些协同效益，而且使恢复项目更容易失败，浪费了宝贵的资源来减少污染物。最后，我们提出了一套关于 SCMs 和河道恢复的综合规划建议，以同时实现水质和河道保护目标。
