Delta flood and drainage: Difference between revisions

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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 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==
*[[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 infrastructure.  Improvement in drainage
*[[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 infrastructure.  Improvement in drainage
*[[Wiley Slough Restoration]] produced controversy and potential economic losses for neighboring land owners by reducing adjacent field drainage.
*[[Wiley Slough Restoration]] produced controversy and potentially 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.
*[[Fir Island Farm Restoration]] 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]] gained local support by providing a flood gate to reduce flooding on Florence Island during an over levee river flood event.
*[[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==
==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 16:07, 28 October 2014


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Link to List of Workgroups Link to List of Topics Link to List of Places

Link to List of Efforts Link to List of Products Link to List of Documents Link to List of Graphics Link to List of Websites

Link to Delta Sites Link to Embayment Sites Link to Beach Sites Link to Rocky Headland Sites

Link to Headwater Sites Link to Lowland Watershed Sites Link to Floodplain Sites

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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 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

The following pages are associated with Delta sediment dynamics and vegetation:

Sub-topics Efforts

Summary[edit]

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[edit]

  • 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 infrastructure. Improvement in drainage
  • Wiley Slough Restoration produced controversy and potentially 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, and is completing additional pre-restoration ground water monitoring to avoid unverifiable claims of injury from restoration actions.
  • Port Susan Restoration gained local support by providing a flood gate to reduce flooding on Florence Island during an over levee river flood event.

Potential Ideas for Future Work[edit]

  • 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