Dynamic Management of Water Storage for Flood Control in a Wetland System: A Case Study in Texas

Abstract

In this study, we assess the costs and benefits of dynamic management of water storage to improve flood control in a system of wetlands. This management involves releasing water from wetlands ahead of (e.g., a few hours or days before) a rainfall event that is forecasted to produce flooding. Each project site may present different challenges and topographical conditions, however as long as there is a relatively small hydraulic gradient between the wetland water surface and the drainage ditch (e.g., >0.9 m), wetlands can be engineered for the purpose of flood control. We present a case study for a system comprised of four wetland areas encompassing 925 acres in the coastal plain south of Houston, Texas. The benefit-cost analysis shows that, in general, the benefits of wetland ecosystems far surpass the costs of construction and maintenance for all considered periods of analysis and assumed degrees of dynamic management of wetland storage. The analysis also shows that the benefit/cost ratios increase over the period of analysis. Considering flood protection only (e.g., not considering the value of other ecosystem services), as long as dynamic management of wetland storage increases flood protection by about 50% compared to that with no management (e.g., a typical wetland with no controlled release of water), the construction of a wetland system would have a benefit/cost ratio of at least 1.9.

LUCC and Ecosystem Service Value Assessment for Wetlands: A Case Study in Nansi Lake, China

“…The high-flow period area is the lake surface area of Nansi Lake wetland beside shoals and islands. (7) Recreation Cultural services relate to the non-material world, as they benefit the benefit recreational, aesthetic, cognitive and spiritual activities, which are not easily quantifiable in monetary terms [58]. The Nansi Lake wetland has many popular tourist attractions e.g., Weishan Lake national wetland park, Weishan Island, Nanyang ancient town, Honghe wetland and Qiandao wetland.…”

“…The ecosystem services value (ESV) of wetland is among the highest of any ecosystem assessed [1,3]. Wetlands supply a variety of resources for human's production and life, and provide via ecological services either directly or indirectly including climate regulation, water conservation, purification, soil conservation and biodiversity protection [4][5][6][7], which have played an important role throughout history to secure human well-being, as well as the social and cultural evolution of humankind [3,8,9]. However, with the rapid population growth and excessive resource consumption, the stability and biodiversity of wetland ecosystem were seriously damaged [6,10,11].…”

Long-Term Monitoring of a Surface Flow Constructed Wetland Treating Agricultural Drainage Water in Northern Italy

“…Compared to conventional wastewater treatment plants, CWs are less costly, easier to operate, and require less maintenance [2]. In addition to their general ability to improve wastewater quality, CWs are multifunctional systems that can offer different ecosystem services [3], including supporting habitat and biodiversity functions, together with recreational and socioeconomic services, including flood and drought control, water retention, and erosion prevention [4][5][6]. These systems can also be used as a part of water reuse schemes [7,8] and can have positive effects on carbon balance [9].…”

“…Since wetlands can reduce agricultural pollution [18], a broader implementation of CWs has been proposed as a measure for protecting aquatic systems [16,19]. The CW type that is usually applied for agricultural drainage water treatment is the surface flow constructed wetland (SFCW) [4], which has been reported to be able to remove nitrogen and phosphorus at relatively low cost [14]. Although there have been studies that discuss different aspects of this topic, not many of them present the general functioning of these systems over long periods of time.…”

A Remotely-Operated Siphon System for Water Release From Wetlands and Shallow Ponds

“…If the wetland is completely drained, however, species that require standing water, such as fish, will be eliminated. Moreover, if a wetland is drained to a low water level in anticipation of a storm and the storm does not materialize, the wetland will be at risk of drying out completely in the following days due to natural evapotranspiration [13]. Thus, draining involves some risks, which can be minimized by not draining the wetlands fully, and by draining only when the certainty of rain events is very high, which may be achieved in the best of the cases a few hours or days in advance of a predicted storm.…”