Delta flood and drainage: Difference between revisions

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{{topic}}[[Category:River delta]][[category:physical science]] [[category:hydrodynamics]] [[category:ESRPCriticalDynamics]] [[Category:Agriculture]]
{{topic}}[[Category:River delta]][[category:physical science]][[category:flood]][[category:hydrodynamics]] [[category:ESRPCriticalDynamics]] [[Category:Agriculture]]
{{delta core topic}}
{{delta core topic}}
'''Agriculture and settlements in deltas commmonly depend on a set of flood defenses and [[drainage systems]] to manage water levels.  Restoration can either enhance or undermine these systems, and flood and drainage systems may in turn have impacts of [[ecosystem services]].  Social acceptance of restoration may depend on our ability to use restoration to predict and enhance flood and drainage function on adjacent lands'''
'''Agriculture and settlements in deltas commmonly depend on a set of flood defenses, drain ditches, and tide gates to manage ground and surface water levels.  Restoration can either enhance or undermine these systems, affecting the communities and economies working in delta agriculture.  Social acceptance of restoration may depend on our ability to use restoration to predict and enhance flood and drainage functions on adjacent lands.'''


The following pages are associated with Delta sediment dynamics and vegetation:
Two sub-topics are proposed for exploration.  Being able to predict the effects of restoration on farm systems is a critical component of restoration feasibility.  Second, being able to describe how resilient marsh helps enhance flood defences may prove useful for management of sea-facing dikes.  Finally, using hydrodynamic modelling to describe the flood benefits of increasing storage and conveyance through levee setbacks may have value, not only in deltas, but also in [[Floodplains]].
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==Summary==
==Summary==
The ability to accurately predict changes in flooding and drainage of agricultural land as a direct result of restoration project actions represents a key uncertainty in our ability to predict the benefits of these actions to adjacent landowners and community stakeholders in general.  Currently there are sea level rise predictive models and hydrologic models that incorporate change in snowpack and participation that describe flood frequency, duration and storage capacity.  There are also storm protection models to address impacts to human stakeholders living in or near river delta environmentsSee [[Floods and Drainage Methods]]
Our inability to accurately predict changes in flooding and drainage of agricultural land as a result of restoration actions prevents us from describing the benefits of restoration to adjacent landowners and community stakeholders.   


Current infrastructure lacks the capacity to adequately handle drainage and store floodwaters as well as providing habitat value.
Curent hydrologic models can incorporate sea level rise predictions, change in snowpack and precipitation, and storage to describe flood frequency and duration.  There are also storm protection models to describe risks to people living in river delta environments (see [[Floods and Drainage Methods]]).


Flooding relief and improved drainage are two of the many socioeconomic benefits that river delta restoration projects deliver as valued ecosystem services to river delta communities.  Removing levees and levee setbacks reduce inundation periods, increase channel-flow conveyance and increase floodplain capacity as well as improving drainage of properties in the vicinity of river deltasFrom a flood-management perspective, there are three ways a project may reduce flooding vulnerability in the community: reducing inundation periods, increasing channel-flow conveyance and increasing floodplain capacity.  These benefits are dependent on site specific vulnerabilities related to sea level rise and other climate change impacts so sea level modeling, in addition to hydrodynamic modeling, is often associated with predicting and measuring changes in flood storage and drainage.  Monitoring questions relate to a project’s ability to improve the site’s capacity to moderate storm-related flooding and the potential for improved resilience to climate change (Brophy and Van de Wetering 2011).
Current infrastructure was designed to handle historical hydrology, while radically decreasing habitat servicesA future infrastructure could be designed to manage changing hydrology while increasing habitat services.


===Methods and Issues===
Flooding relief and improved drainage are two of the many socioeconomic benefits that river delta restoration projects could deliver to river delta communities. Removing levees and levee setbacks could be designed to incorporate flood and drainage benefits.
Flooding relief and improved drainage are two of the many socioeconomic benefits that river delta restoration projects deliver as valued ecosystem services to river delta communities. Removing levees and levee setbacks reduce inundation periods, increase channel-flow conveyance and increase floodplain capacity as well as improving drainage of properties in the vicinity of river deltas. From a flood-management perspective, there are three ways a project may reduce flooding vulnerability in the community: reducing inundation periods, increasing channel-flow conveyance and increasing floodplain capacity. These benefits are dependent on site specific vulnerabilities related to sea level rise and other climate change impacts so sea level modeling, in addition to hydrodynamic modeling, is often associated with predicting and measuring changes in flood storage and drainage. Monitoring questions relate to a project’s ability to improve the site’s capacity to moderate storm-related flooding and the potential for improved resilience to climate change (Brophy and Van de Wetering 2011).


==Related Efforts==
From a flood-management perspective, there are three ways a project may reduce flooding vulnerability in the community: 1) reducing inundation periods, 2) increasing channel-flow conveyance, and 3) increasing floodplain capacity.  In addition, improvement in ground water drainage between tidal cycles can improve the productivity of agricultural lands.  The ability to gain these benefits dependds on the siteSite analysis and post project monitoring can be used to measure these benefits, and to verify the potential for improved resilience to climate change (Brophy and Van de Wetering 2011).
*[[Fisher Slough Restoration]] increased flood storage and conveyance on Carpenter Creek--[[Weinerman et al 2012]] documents economic benefits from restoration.  The project provided a significant renovation of drainage infrastructureImprovement in drainage
*[[Wiley Slough Restoration]] produced controversy and potential economic losses for neighboring land owners by reducing adjacent field drainage.
*[[Fir Island Farm Restoration]] is completing feasibility work to evaluate potential effects on drainage.
*[[Port Susan Restoration]] gained local support by providing a flood gate to reduce flooding on Florence Island during an over levee river flood event.


==Potentially Useful Efforts==
Because tidal flood interacts with river flood, and affects drainage, future sea level modeling, in addition to hydrodynamic modeling, is often associated with predicting and measuring changes in flood storage and drainage.
 
==Notes==
*[[Fisher Slough Restoration]] in the [[Skagit Delta]] increased flood storage and conveyance on Carpenter Creek--[[Weinerman et al 2012]] documents economic benefits from restoration.  The project provided a significant renovation of drainage infrastructure.  Improvement in drainage
*[[Wiley Slough Restoration]] in the [[Skagit Delta]] produced controversy and potentially economic losses for neighboring land owners by reducing adjacent field drainage. 
*[[Fir Island Farm Restoration]] in the [[Skagit Delta]] is completing feasibility work to evaluate potential effects on drainage, and is completing additional pre-restoration ground water monitoring to avoid unverifiable claims of injury from restoration actions.
*[[Port Susan Restoration]] in the [[Stillaguamish Delta]] gained local support by providing a flood gate to reduce flooding on Florence Island during an over levee river flood event.
*The [[Tidegate Fish Initiative]] in the [[Skagit Delta]] links drainage repair and upgrades to restoration actions using a credit trading system as a way to resolve impacts to endangered Chinook salmon.
*The [[Farm, Fish and Flood Initiative]] in the [[Skagit Delta]], is coordinating planning between agricultural preservation, restoration, and flood management, to define a suite of projects with the maximum community benefits.
*The [[Snohomish Sustainable Lands Strategy]] is working in the [[Stillaguamish Delta]] and [[Snohomish Delta]] to identify a suite of actions that provide multiple benefits for fishery restoration and agriculture.
 
==Potential Ideas for Future Work==
*Predict functions from differing configurations of drainage, storage, tide gating, and restoration to maximize both field drainage and habitat function in a delta setting
*Predict functions from differing configurations of drainage, storage, tide gating, and restoration to maximize both field drainage and habitat function in a delta setting
*Develop and reduce costs of robust standard methods to predict the reduction in frequency and/or duration of flood events resulting from project change in flood storage capacity scenarios
*Develop and reduce the costs of robust standard methods to predict the reduction in frequency and/or duration of flood events resulting from restoration projects.
*Develop and reduce costs of robust standard methods to predict the effect of climate change parameters (sea level rise, reduced snowpack storage, reduced precipitation, etc) on future flood frequency and duration===
*Develop and reduce the costs of robust standard methods to predict the effect of climate change parameters (sea level rise, reduced snowpack storage, reduced precipitation, etc) on future flood frequency and duration
*Develop and reduce costs for standard method for predicting how tidal reconnection affects field drainage and groundwater salinity at timing important for agricultural stakeholders===
*Develop and reduce the costs of standard method for predicting how tidal reconnection affects field drainage and groundwater salinity at times important for agricultural stakeholders

Revision as of 18:47, 28 December 2016


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This page is a core topic for River Deltas as developed by the River Delta Adaptive Management Strategy

Agriculture and settlements in deltas commmonly depend on a set of flood defenses, drain ditches, and tide gates to manage ground and surface water levels. Restoration can either enhance or undermine these systems, affecting the communities and economies working in delta agriculture. Social acceptance of restoration may depend on our ability to use restoration to predict and enhance flood and drainage functions on adjacent lands.

Two sub-topics are proposed for exploration. Being able to predict the effects of restoration on farm systems is a critical component of restoration feasibility. Second, being able to describe how resilient marsh helps enhance flood defences may prove useful for management of sea-facing dikes. Finally, using hydrodynamic modelling to describe the flood benefits of increasing storage and conveyance through levee setbacks may have value, not only in deltas, but also in Floodplains.

Sub-topics Efforts

Summary

Our inability to accurately predict changes in flooding and drainage of agricultural land as a result of restoration actions prevents us from describing the benefits of restoration to adjacent landowners and community stakeholders.

Curent hydrologic models can incorporate sea level rise predictions, change in snowpack and precipitation, and storage to describe flood frequency and duration. There are also storm protection models to describe risks to people living in river delta environments (see Floods and Drainage Methods).

Current infrastructure was designed to handle historical hydrology, while radically decreasing habitat services. A future infrastructure could be designed to manage changing hydrology while increasing habitat services.

Flooding relief and improved drainage are two of the many socioeconomic benefits that river delta restoration projects could deliver to river delta communities. Removing levees and levee setbacks could be designed to incorporate flood and drainage benefits.

From a flood-management perspective, there are three ways a project may reduce flooding vulnerability in the community: 1) reducing inundation periods, 2) increasing channel-flow conveyance, and 3) increasing floodplain capacity. In addition, improvement in ground water drainage between tidal cycles can improve the productivity of agricultural lands. The ability to gain these benefits dependds on the site. Site analysis and post project monitoring can be used to measure these benefits, and to verify the potential for improved resilience to climate change (Brophy and Van de Wetering 2011).

Because tidal flood interacts with river flood, and affects drainage, future sea level modeling, in addition to hydrodynamic modeling, is often associated with predicting and measuring changes in flood storage and drainage.

Notes

Potential Ideas for Future Work

  • Predict functions from differing configurations of drainage, storage, tide gating, and restoration to maximize both field drainage and habitat function in a delta setting
  • Develop and reduce the costs of robust standard methods to predict the reduction in frequency and/or duration of flood events resulting from restoration projects.
  • Develop and reduce the costs of robust standard methods to predict the effect of climate change parameters (sea level rise, reduced snowpack storage, reduced precipitation, etc) on future flood frequency and duration
  • Develop and reduce the costs of standard method for predicting how tidal reconnection affects field drainage and groundwater salinity at times important for agricultural stakeholders