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4.3 Integrative Planning
One component of more effective river restoration is thinking carefully about integration across space and through time: that is the intention of the phrase ‘integrative
planning.’ Integration across diverse spatial scales is critically important because of
the many forms of connectivity within a watershed and between the watershed and
the greater environment. Many forms of river restoration are implemented within a
limited spatial scale: the operating regime of a single dam is modified or the erosional resistance of a limited length of river bank is enhanced by restoring woody
riparian vegetation. The ability of restoration activities to achieve desired ends,
however, may well depend on factors outside the restoration area. Modifying the
operating regime of the dam may not restore desired native fish communities, for
example, because introduced species continue to outcompete native species.
Recovery of woody riparian vegetation may not sufficiently increase nitrate uptake
and processing because nitrate loads coming from upstream portions of the watershed overwhelm the uptake capacity of the restored segment of river corridor.
Thinking about a segment of river corridor as connected longitudinally, laterally,
and vertically also facilitates consideration of factors outside of the active channel
that might limit restoration success. An example comes from a project to restore
native riparian willows along a formerly vegetated river corridor in California,
USA. Willows planted at the site were unable to survive because ground water
pumping had lowered regional and riparian water tables below a level that willows
could access with their roots (Kondolf 1996).
Planning restoration activities in the context of processes operating across diverse
spatial scales is particularly critical because the great majority of drainage basins
have multiple historical and contemporary human alterations and stressors
(Frothingham et al. 2002). It may not be feasible to restore a formerly meandering
river segment that is now braided, for example, without addressing continuing bank
instability and high sediment inputs from former mining upstream (Hilmes and
Wohl 1995). And it may not be feasible to restore a formerly braided river segment
that now meanders through a densely vegetated river corridor without addressing
the upstream flow regulation that prevents occurrence of peak flows capable of
eroding banks and removing vegetation, as on the Platte River in Nebraska, USA
(NRC 2004; Smith 2011) (Fig. 4.5).
Finally, thinking about restoration as applied to drainage basins or entire river
networks rather than solely to limited segments of a river can help to prioritize the
temporal and spatial scope of restoration activities. Examples come from the Upper
Mississippi River and one of its principal tributaries, the Illinois River. Both rivers
have been extensively and intensively altered to facilitate agriculture and settlement
in valley bottoms (land drainage, floodplain forest clearance, levees, flood control)
and navigation (locks and dams, dredging, channelization) (Wohl 2004, 2011,
2013). Agriculture, urbanization, and navigation continue in these river networks,
but restoration activities focus on what are sometimes referred to as beads along
these rivers.
4 Toward Sustainable Rivers and Water Resources
4.3 Integrative Planning
One component of more effective river restoration is thinking carefully about integration across space and through time: that is the intention of the phrase ‘integrative
planning.’ Integration across diverse spatial scales is critically important because of
the many forms of connectivity within a watershed and between the watershed and
the greater environment. Many forms of river restoration are implemented within a
limited spatial scale: the operating regime of a single dam is modified or the erosional resistance of a limited length of river bank is enhanced by restoring woody
riparian vegetation. The ability of restoration activities to achieve desired ends,
however, may well depend on factors outside the restoration area. Modifying the
operating regime of the dam may not restore desired native fish communities, for
example, because introduced species continue to outcompete native species.
Recovery of woody riparian vegetation may not sufficiently increase nitrate uptake
and processing because nitrate loads coming from upstream portions of the watershed overwhelm the uptake capacity of the restored segment of river corridor.
Thinking about a segment of river corridor as connected longitudinally, laterally,
and vertically also facilitates consideration of factors outside of the active channel
that might limit restoration success. An example comes from a project to restore
native riparian willows along a formerly vegetated river corridor in California,
USA. Willows planted at the site were unable to survive because ground water
pumping had lowered regional and riparian water tables below a level that willows
could access with their roots (Kondolf 1996).
Planning restoration activities in the context of processes operating across diverse
spatial scales is particularly critical because the great majority of drainage basins
have multiple historical and contemporary human alterations and stressors
(Frothingham et al. 2002). It may not be feasible to restore a formerly meandering
river segment that is now braided, for example, without addressing continuing bank
instability and high sediment inputs from former mining upstream (Hilmes and
Wohl 1995). And it may not be feasible to restore a formerly braided river segment
that now meanders through a densely vegetated river corridor without addressing
the upstream flow regulation that prevents occurrence of peak flows capable of
eroding banks and removing vegetation, as on the Platte River in Nebraska, USA
(NRC 2004; Smith 2011) (Fig. 4.5).
Finally, thinking about restoration as applied to drainage basins or entire river
networks rather than solely to limited segments of a river can help to prioritize the
temporal and spatial scope of restoration activities. Examples come from the Upper
Mississippi River and one of its principal tributaries, the Illinois River. Both rivers
have been extensively and intensively altered to facilitate agriculture and settlement
in valley bottoms (land drainage, floodplain forest clearance, levees, flood control)
and navigation (locks and dams, dredging, channelization) (Wohl 2004, 2011,
2013). Agriculture, urbanization, and navigation continue in these river networks,
but restoration activities focus on what are sometimes referred to as beads along
these rivers.
4 Toward Sustainable Rivers and Water Resources