Hyporheic rehabilitation in rivers: restoring vertical connectivity

Abstract

1. The hyporheic zone below the channel and banks of many rivers where surface water and ground water exchanges plays a crucial functional role in the biogeochemical transformation of water, mediated by active microbial biofilms. This zone also harbours assemblages of invertebrates that graze biofilms, contribute to secondary production, and can alter the porosity of the hyporheic zone through their movement or burrowing activities. 2. Many human activities cause interstitial sedimentation or disrupt surface-groundwater hydrological linkages, impacting upon ecological processes in the hyporheic zone. However, strategies for river rehabilitation seldom explicitly consider the hyporheic zone or seek to restore lost vertical linkages with groundwater. Instead, restoration goals target surface, riparian or floodplain features even though current river ecosystem theory emphasises the three dimensions of hydrological connectivity. To guide effective, holistic river restoration, scientists and managers therefore need information on the mechanisms by which energy and material are transferred in the hyporheic zone and which ecosystem services are thus provided. 3. Other gaps in our understanding of hyporheic zone rehabilitation include recruitment processes of the hyporheos and the relative importance of groups of hyporheic invertebrates in rivers differing in substratum size, disturbance frequency and groundwater linkages. Carefully designed experiments that assess responses to hyporheic rehabilitation strategies will provide valuable data at varying scales (e.g. distribution of hyporheic habitat types at the reach scale) for management as well as providing insights into the mechanisms controlling hyporheic invertebrate assemblages and ecological processes. Fully successful river rehabilitation must include restoration of vertical linkages between the river and its shallow groundwater aquifers.

Spatial patterns of hyporheic exchange and biogeochemical cycling around cross‐vane restoration structures: Implications for stream restoration design

“…Clearly these viewpoints are not mutually exclusive, and both are important in hyporheic restoration [Boulton, 2007;Hester and Gooseff, 2010]. However, the results of this study suggest that the benthic-centric perspective is more applicable to the hyporheic zone in the restored stream reaches studied here, which are representative of many agricultural, lowland streams in Central New York in slope, sinuosity, bed material, and history of degradation and restoration, although differences in K could alter these conclusions for other streams.…”

“…Boulton [2007], Boulton et al [2010], and Gooseff [2010, 2011] have emphasized the importance of the hyporheic zone in ecological restoration and called for a more complete approach to river restoration that includes hyporheic processes. However, postconstruction assessment of restoration projects is not widespread [Bernhardt et al, 2005[Bernhardt et al, , 2007Nagle, 2007], and few studies have investigated the impact of instream restoration structures on hyporheic exchange fluxes or water chemistry, with some notable exceptions Hill, 2006a, 2006b;Fanelli and Lautz, 2008;Kasahara and Hill, 2008;Lautz and Fanelli, 2008].…”

Investigating patterns and controls of groundwater up-welling in a lowland river by combining Fibre-optic Distributed Temperature Sensing with observations of vertical hydraulic gradients

“…Hydrological sciences have experienced a significant paradigm shift in recent years, advancing the rather static perception of rivers and aquifers as discrete entities towards a more complex and dynamic understanding of groundwater and surface water as integral components of a streamcatchment continuum (Bencala, 1993;Brunke and Gonser, 1997;Boulton et al, 1998;Boulton, 2007;Sophocleous, 2002;Krause et al, 2009aKrause et al, , 2011aWoessner, 2000). The hyporheic zone (HZ), i.e.…”

Reshaping of the hyporheic zone beneath river restoration structures: Flume and hydrodynamic experiments

“…[4] River engineers and scientists have called for investigations into the influence of river restoration on hyporheic exchange at the local scale and reach scale [Boulton, 2007;Boulton et al, 2010;Hancock, 2002;Hester and Gooseff, 2010;Krause et al, 2011]. While field experiments do not have glass-walled viewing of the local exchange, Lautz and Fanelli [2008] used piezometer sampling to investigate the spatial biogeochemical patterns around a channel-spanning restoration structure in a pool-riffle river.…”