Post-Project Appraisals in Adaptive Management of River Channel Restoration

Post-project appraisals (PPAs) can evaluate river restoration schemes in relation to their compliance with design, their short-term performance attainment, and their longer-term geomorphological compatibility with the catchment hydrology and sediment transport processes. PPAs provide the basis for communicating the results of one restoration scheme to another, thereby improving future restoration designs. They also supply essential performance feedback needed for adaptive management, in which management actions are treated as experiments. PPAs allow river restoration success to be defined both in terms of the scheme attaining its performance objectives and in providing a significant learning experience. Different levels of investment in PPA, in terms of pre-project data and follow-up information, bring with them different degrees of understanding and thus different abilities to gauge both types of success. We present four case studies to illustrate how the commitment to PPA has determined the understanding achieved in each case. In Moore's Gulch (California, USA), understanding was severely constrained by the lack of pre-project data and post-implementation monitoring. Pre-project data existed for the Kitswell Brook (Hertfordshire, UK), but the monitoring consisted only of one site visit and thus the understanding achieved is related primarily to design compliance issues. The monitoring undertaken for Deep Run (Maryland, USA) and the River Idle (Nottinghamshire, UK) enabled some understanding of the short-term performance of each scheme. The transferable understanding gained from each case study is used to develop an illustrative five-fold classification of geomorphological PPAs (full, medium-term, short-term, one-shot, and remains) according to their potential as learning experiences. The learning experience is central to adaptive management but rarely articulated in the literature. Here, we gauge the potential via superimposition onto a previous schematic representation of the adaptive management process by Haney and Power (1996). Using PPAs wisely can lead to cutting-edge, complex solutions to river restoration challenges.

[1]  Yeou-Koung Tung.  Channel scouring potential using logistic analysis , 1985 .

[2]  N. A. Binns.  Long‐Term Responses of Trout and Macrohabitats to Habitat Management in a Wyoming Headwater Stream , 1994 .

[4]  G. Mathias Kondolf,et al.  Historical channel analysis and its application to riparian and aquatic habitat restoration , 1995 .

[5]  Ken D. Bovee,et al.  A guide to stream habitat analysis using the Instream Flow Incremental Methodology. IFIP No. 12 , 1982 .

[6]  Ronald M. Thom,et al.  System-development matrix for adaptive management of coastal ecosystem restoration projects , 1997 .

[7]  E. W. Lane.  The Importance of Fluvial Morphology in Hydraulic Engineering , 1955 .

[8]  D. Gilvear,et al.  Image analysis of aerial photography to quantify changes in channel morphology and instream habitat following placer mining in interior Alaska , 1995 .

[9]  Mervyn Bramley,et al.  Protection of River and Canal Banks: A Guide to Selection and Design , 1989 .

[10]  A. Brookes.  Restoring the sinuosity of artificially straightened stream channels , 1987 .

[11]  Peter W. Downs,et al.  Estimating the probability of river channel adjustment , 1995 .

[12]  Peter W. Downs,et al.  Design principles and suitability testing for rehabilitation in a flood defence channel: the River Idle, Nottinghamshire, UK , 1998 .

[13]  Govert D. Geldof.  Adaptive water management: integrated water management on the edge of chaos , 1995 .

[14]  G. Mathias Kondolf,et al.  Evaluating stream restoration projects , 1995 .

[15]  S. Schumm,et al.  Time, space, and causality in geomorphology , 1965 .

[16]  D. Sear.  River restoration and geomorphology , 1994 .

[17]  Peter W. Downs,et al.  Rehabilitation of a lowland river: Reconciling flood defence with habitat diversity and geomorphological sustainability , 2000 .

[18]  Colin R. Thorne,et al.  Channel Restoration Design for Meandering Rivers , 2001 .

[19]  P. Downs.  Characterization of river channel adjustments in the thames basin, south‐east England , 1994 .

[20]  Mark J. Wieringa,et al.  Hydropower, adaptive management, and Biodiversity , 1996, Environmental management.

[21]  J. Phillips.  The end of equilibrium , 1992 .

[22]  Henry Petroski,et al.  To Engineer Is Human: The Role of Failure in Successful Design , 1986 .

[23]  G. Mathias Kondolf,et al.  Five Elements for Effective Evaluation of Stream Restoration , 1995 .

[24]  S. Rice.  Which tributaries disrupt downstream fining along gravel-bed rivers? , 1998 .

[25]  Henry Mintzberg.  Beyond Implementation: An Analysis Of The Resistance To Policy Analysis† , 1980 .

[26]  G. Mathias Kondolf,et al.  Geomorphological stream channel classification in aquatic habitat restoration: Uses and limitations , 1995 .

[27]  P. Downs,et al.  Developing Geomorphic Post Project Appraisals for Environmentally-Aligned River Channel Management , 1997 .

[28]  Colin R. Thorne,et al.  Stream Reconnaissance Handbook: Geomorphological Investigation and Analysis of River Channels , 1998 .

[29]  Karina Mrakovcich,et al.  Sailing the Shoals of Adaptive Management: The Case of Salmon in the Pacific Northwest , 1998, Environmental management.

[30]  P. Downs,et al.  Uncertainty in the Engineering of Wildlife Habitats , 1998 .

[31]  R. McLain,et al.  Adaptive management: Promises and pitfalls , 1996, Environmental management.

[32]  R. Hey.  DETERMINATE HYDRAULIC GEOMETRY OF RIVER CHANNELS , 1978 .

[33]  Alan Haney,et al.  Adaptive management for sound ecosystem management , 1996, Environmental management.