Adaptive management of return flows

lessons from a case study in environmental water delivery to a floodplain river

Benjamin J. Wolfenden*, Skye M. Wassens, Kim M. Jenkins, Darren S. Baldwin, Tsuyoshi Kobayashi, James Maguire

*Corresponding author for this work

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

For many floodplain rivers, reinstating wetland connectivity is necessary for ecosystems to recover from decades of regulation. Environmental return flows (the managed delivery of wetland water to an adjacent river) can be used strategically to facilitate natural ecosystem connectivity, enabling the transfer of nutrients, energy, and biota from wetland habitats to the river. Using an informal adaptive management framework, we delivered return flows from a forested wetland complex into a large lowland river in south-eastern Australia. We hypothesized that return flows would (a) increase river nutrient concentrations; (b) reduce wetland nutrient concentrations; (c) increase rates of ecosystem metabolism through the addition of potentially limiting nutrients, causing related increases in the concentration of water column chlorophyll-a; and (d) increase the density and species richness of microinvertebrates in riverine benthic habitats. Our monitoring results demonstrated a small increase in the concentrations of several key nutrients but no evidence for significant ecological responses was found. Although return flows can be delivered from forested floodplain areas without risking hypoxic blackwater events, returning nutrient and carbon-rich water to increase riverine productivity is limited by the achievable scale of return flows. Nevertheless, using return flows to flush carbon from floodplains may be a useful management tool to reduce carbon loads, preparing floodplains for subsequent releases (e.g., mitigating the risk of hypoxic blackwater events). In this example, adaptive management benefited from a semi-formal collaboration between science and management that allowed for prompt decision-making.

Original languageEnglish
Pages (from-to)481-496
Number of pages16
JournalEnvironmental Management
Volume61
Issue number3
Early online date4 May 2017
DOIs
Publication statusPublished - Mar 2018
Externally publishedYes

Keywords

  • Connectivity
  • Dissolved organic carbon
  • Ecosystem metabolism
  • Flow regulation
  • Microinvertebrate

Fingerprint Dive into the research topics of 'Adaptive management of return flows: lessons from a case study in environmental water delivery to a floodplain river'. Together they form a unique fingerprint.

  • Cite this

    Wolfenden, B. J., Wassens, S. M., Jenkins, K. M., Baldwin, D. S., Kobayashi, T., & Maguire, J. (2018). Adaptive management of return flows: lessons from a case study in environmental water delivery to a floodplain river. Environmental Management, 61(3), 481-496. https://doi.org/10.1007/s00267-017-0861-0