Assessing the Performance of In-Stream Restoration Projects Using Radio Frequency Identification (RFID) Transponders

Abstract

Abstract:Instream channel restoration is a common practice in river engineering that presents a challenge for research. One research gap is the development of monitoring techniques that allow for testable predictions of sediment transport and supply. Here we use Radio Frequency Identification (RFID) transponders to compare the short-term (1-year) sediment transport response to flood events in a restored and a control reach. The field site is Wilket Creek, an enlarged creek in a fully urbanized catchment without stormwater management control in Toronto, Ontario. The responses to three flooding periods, each of which are at or above the design bankfull discharge, are described. Key results are that (i) particle mobility is lower in the restored reach for all three periods; (ii) full mobility occurs in the control reach during the first two floods while partial mobility occurs in the restored reach; and (iii) the constructed morphology exerted a controlling influence on particle entrainment, with higher mobility in the pools. Log-transformed travel distances exhibit normal distributions when grouped by particle size class, which allows a statistical comparison with power law and other predictive travel-distance relations. Results show that three bedload transport conditions can occur, with partial mobility associated with a OPEN ACCESSWater 2015, 7 5567 mild relation between particle size and travel distance and full mobility associated with either a flat or steep relation depending on the degree of integration of particles in the bed. Recommendations on seeding strategy and sample sizes are made to improve the precision of the results by minimizing confidence intervals for mobility and travel distances. Even in a short term study, the RFID sediment tracking technique allows a process-based assessment of stream restoration outcomes that can be used to justify the instream intervention and plan future attempts to stabilize and enhance the system.

Restoring in‐stream habitat in urban catchments: Modify flow or the channel?

“…Restoration efforts, once both the flow and channel are changed, will require an integrated approach. For instance, there may be opportunities to accompany catchment‐scale flow mitigation works with promotion of self‐regeneration of stream morphology including sediment seeding and the stream self‐organizing sediments (MacVicar, Chapuis, Buckrell, & Roy, ; Wilcock, ) to minimize erosion and mobility. In other cases, direct intervention to modify the channel morphology may need to accompany the flow mitigation effort.…”

Monitoring the effectiveness of floodplain habitat restoration: A review of methods and recommendations for future monitoring

“…Categorical mapping of sediment storage areas (gravel bars, age of riparian vegetation) based on how often sediment has moved can also be used to estimate areas of channel and floodplain sediment storage (Madej, ; Pess et al, ). PIT tags (radio frequency identification [RFID] transponders) can also be used to examine sediment transport (MacVicar, Chapuis, Buckrell, & Roy, ). Many of these approaches are only feasible for very intensive monitoring of one or a few floodplain restoration projects.…”

Enlargement and evolution of a semi‐alluvial creek in response to urbanization

“…Questions about the costs of ongoing maintenance and the possibility of ameliorating the ecosystem services of urban creeks and rivers led to a city-wide hydrologic and geomorphic study in the 1990s (D'andrea et al, 2004). A study of the impact of this approach on sediment dynamics showed it successfully reduced the frequency of transport decreased for gravel and cobble sized material (MacVicar et al, 2015) though the long-term implications remain uncertain. Several floods in the 2000s caused widespread erosion of natural and previously stabilized bed and banks (Figure 2), which led to the creation of a stabilization plan to control erosion and minimize the risk to infrastructure in the watershed (Parish Geomorphic, 2011).…”

“…A significant portion of the lower reach (~1 km or 50%) has now been rebuilt following a constructed riffle-pool approach. A study of the impact of this approach on sediment dynamics showed it successfully reduced the frequency of transport decreased for gravel and cobble sized material (MacVicar et al, 2015) though the long-term implications remain uncertain. The question of channel enlargement and an appropriate model for channel evolution in response to urbanization remain of significant interest for guiding future management efforts.…”