Influence of Near‐to‐Nature Stormwater Management on the Local Water Balance Using the Example of an Urban Development Area

Hopkins

et al. 2017

150

128

Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small‐scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention‐based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non‐additive effects of individual SCMs; and persistence of urban effects beyond impervious surfaces. In most cases, pollutant load decreases largely result from run‐off reductions rather than lowered solute or particulate concentrations. Understanding interactions between natural and built landscapes, including stormwater management strategies, is critical for successfully managing detrimental impacts of stormwater at the watershed scale.

Section: Results Of Existing Studiesmentioning

confidence: 99%

Stormwater management network effectiveness and implications for urban watershed function: A critical review

Jefferson

Hopkins

et al. 2017

150

128

“…Infiltration through stormwater facilities. Infiltrationfocused stormwater facilities may lead to more recharge from point sources instead of diffuse sources (Appleyard, 1995), which has been suggested to increase annual recharge (Ku et al, 1992;Göbel et al, 2004;Stephens et al, 2012;Barron et al, 2013;Hamel and Fletcher, 2014), although not in all cases (Keßler et al, 2012). Ideally with LID, the goal is for the urbanized water cycle to be equivalent to the pre-development cycle in overall fluxes (i.e.…”

Section: Introduction Of Directly Connected Impervious Surfacesmentioning

confidence: 99%

“…Studies have also investigated the effect of LID on groundwater recharge, where recharge is that part of infiltrated water not taken up by plants or evaporated but instead reaches the water table (Healy, ). These studies have revealed that (1) the effect of stormwater infiltration on recharge depends strongly on pre‐development recharge (Ku et al , ; Keßler et al , ; Stephens et al , ; Thomas and Vogel, ) and (2) groundwater mounding beneath stormwater facilities is more prevalent with low hydraulic conductivity, centralized spatial arrangement, or positioning at topographic lows (Endreny and Collins, ; Carleton, ; Machusick et al , ). Groundwater mounding may cause unintended damage to infrastructure, such as flooding of underground structures, groundwater leakage into wastewater pipes, vegetation damage, and pollutant mobilization (Göbel et al , ).…”

Section: Introductionmentioning

confidence: 99%

Urban base flow with low impact development

Hogan

Archfield

2016

Abstract:A novel form of urbanization, low impact development (LID), aims to engineer systems that replicate natural hydrologic functioning, in part by infiltrating stormwater close to the impervious surfaces that generate it. We sought to statistically evaluate changes in a base flow regime because of urbanization with LID, specifically changes in base flow magnitude, seasonality, and rate of change. We used a case study watershed in Clarksburg, Maryland, in which streamflow was monitored during whole-watershed urbanization from forest and agricultural to suburban residential development using LID. The 1.11-km 2 watershed contains 73 infiltration-focused stormwater facilities, including bioretention facilities, dry wells, and dry swales. We examined annual and monthly flow during and after urbanization (2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014) and compared alterations to nearby forested and urban control watersheds. We show that total streamflow and base flow increased in the LID watershed during urbanization as compared with control watersheds. The LID watershed had more gradual storm recessions after urbanization and attenuated seasonality in base flow. These flow regime changes may be because of a reduction in evapotranspiration because of the overall decrease in vegetative cover with urbanization and the increase in point sources of recharge. Precipitation that may once have infiltrated soil, been stored in soil moisture to be eventually transpired in a forested landscape, may now be recharged and become base flow. The transfer of evapotranspiration to base flow is an unintended consequence to the water balance of LID.

“…Previous work has used modelling to examine the potential effects of infiltrationbased stormwater facilities on groundwater levels beneath individual facilities (e.g., Machusick, Welker, & Traver, 2011;Newcomer, Gurdak, Sklar, & Nanus, 2014) and resulting from multiple facilities (Barron, Barr, & Donn, 2013;Carleton, 2010;Endreny & Collins, 2009;Göbel et al, 2004;Holman-Dodds, Bradley, & Potter, 2003;Ku, Hagelin, & Buxton, 1992;Locatelli et al, 2017;Maimone, O'Rourke, Knighton, & Thomas, 2011;Shuster, Gehring, & Gerken, 2007;Stephens, Miller, Moore, Umstot, & Salvato, 2012;Trinh & Chui, 2013). One monitoring analysis of groundwater elevations indicated that the effect of stormwater infiltration facilities is small but significant in Back Bay, Boston (Thomas & Vogel, 2012), although in another case, the effect of stormwater infiltration on groundwater elevations was not detectible (Keßler, Meyer, Seeling, Tressel, & Krein, 2012).…”

Section: Introductionmentioning

confidence: 99%

Groundwater recharge amidst focused stormwater infiltration

Hogan

Nimmo

et al. 2018

Distributed, infiltration‐based approaches to stormwater management are being implemented to mitigate effects of urban development on water resources. One of the goals of this type of storm water management, sometimes called low impact development or green infrastructure, is to maintain groundwater recharge and stream base flow at predevelopment levels. However, the connection between infiltration‐based stormwater management and groundwater recharge is not straightforward. Water infiltrated through stormwater facilities may be stored in soil moisture, taken up by evapotranspiration or contribute to recharge and eventually base flow. This study focused on a 1.1 km2 suburban, low impact development watershed in Clarksburg, Maryland, USA, that was urbanized and contained 73 infiltration‐based stormwater facilities. Continuous water table measurements were used to quantify the movement of infiltrated stormwater. Time series analyses were performed on hydrographs of 7 wells, and the episodic master recession method was used. Persistence in water levels, as measured by autocorrelation function, was found to be positively related to depth to water. Storm properties (precipitation rate and duration) and well location (proximity to the nearest stream) were significant in driving episodic recharge to precipitation ratios. The well that had the highest recharge to precipitation ratios and water table rises of up to 1.5 m in response to storm events was located furthest from the stream and down gradient of stormwater infiltration locations. This work may be considered in evaluating the effects of planned watershed‐scale infiltration‐based stormwater management on groundwater flow systems.