Better management of construction sites to protect inland waters

Abstract

Several areas within the Lake Simcoe watershed, Canada, are experiencing rapid urban development. The construction of new homes and businesses is frequently associated with elevated rates of soil erosion stemming from land clearing and grading activities. During development, rates of soil erosion can climb to levels that are typically 200 times above background conditions, with the eroded sediments entering waterways and causing harm to the biota living therein. This is a serious challenge for the communities around Lake Simcoe because the transport of sediment has previously been identified as a contributor to the eutrophication of the lake's waters. To mitigate the negative impacts associated with development, many jurisdictions across North America and elsewhere have developed a suite of constructionphase stormwater management (CPSWM) guidelines, which entail the use of onsite best management practices that capture, detain, and treat sediment-laden surface runoff. Here, we review CPSWM guidelines for effluent discharge and receiving water quality and discuss the relative strengths and weaknesses of each approach. Finally, proposed revisions to the current Ontario guidelines are suggested based on a combination of field observations at predevelopment and active construction sites, as well as the reviewed literature. If adopted, the proposed revisions would help to reduce sediment transport from construction sites in rapidly urbanizing areas such as Lake Simcoe.

Event-based design tool for construction site erosion and sediment controls

“…To mitigate the potential negative water quality effects associated with construction sites, many jurisdictions around the world have established a suite of Construction-Phase Stormwater Management (CPSWM) guidelines, which encourage and enforce the use of an extensive list of BMPs with various degrees of effectiveness and cost, and these consist of both erosion prevention and sediment control measures (Trenouth et al, 2013). Guidelines consist of benchmark criteria that CPSWM plans are required to achieve.…”

“…To quantify the potential adverse effect of the construction site on the receiving stream, two water quality monitoring stations are established -one upstream and one downstream of the site in the stream. In Canada, the Canadian Council of Ministers of the Environment (CCME) separates receiving water impacts into conditions where high and low flow conditions exist and also incorporate the length of time elevated conditions may exist (Trenouth et al, 2013).…”

“…EDGs apply to the quality of water being discharged from a construction site (Trenouth et al, 2013). EDGs set target limits for the turbidity of the water based on the tolerance limits of the aquatic species in the receiving streams.…”

Enhancement of sediment phosphorus release during a tunnel construction across an urban lake (Lake Donghu, China)

“…In a sediment core of Lake Huanggaihu, located in the middle reach of the Yangtze River, China, high sediment mass accumulation rates and low clay content suggested increased catchment erosion related to human activities such as railway construction and forest clearing during the 1910s-1940s in the catchment area (Yao and Xue 2015). During urban development, rates of soil erosion can climb to levels that are typically 200 times above background conditions, with the eroded sediments entering waterways and causing harm to the biota living therein, which has been identified as a contributor to the eutrophication of Lake Simcoe (Trenouth et al 2013). In the Feitsui Reservoir, Taiwan, groundwater outbursts carrying Ca exports occurred during tunnel construction at the catchments, which had impacted sediment phosphorus (P) geochemistry (Chen and Wu 2007).…”

Investigating the Spatial and Temporal Variability of Precipitation using Entropy Theory

“…The distribution of precipitation spatially and temporally directly affects the hydrological cycle within a watershed, altering flow regimes and complicating the accurate predictions of flow (Das et al 2008;Boyer et al 2010;Coulibaly 2006;Khan and Coulibaly 2010;Liu and Cui 2011;Trenouth et al 2013;Thompson et al 2016). An understanding of precipitation variability is also needed for flood and drought preparedness planning.…”