6. Database Components – Time-series inundation maps - 1997 Flood

Time-series inundation maps referenced to stage and/or discharge hydrographs of mainstem and tributary streamflow gages are a valuable historical record of the flood. They can be used for a variety of flood analysis. Documentation of breakout flows is also important because of the impact they have in affecting forecasts and in improving model output. The flood extent and breakout data is also useful for model calibration. If done for the 1997 flood, the data could also be used for calibration of automated inundation mapping programs. Because of the complex nature of the 1997 flood, which included several peaks, a time series of images needs to be observed to get a true reconstruction of the flood.

Implementation Strategy: Catalog all RADARSAT images and aerial photographs collected during the 1997 flood event and document any post-processing of flood delineation that has occurred. Process additional scenes/photos to create a complete record of inundation and breakout events..

7. Real-Time Flow Gauging Needs

Accurate flow data is the foundation for all forecasting and modelling activities. Gauges to provide real-time discharge data, especially where looping effects make use of standard ratings impossible, such as at Grand Forks, are critical to improve flood forecasting/monitoring.

Implementation Strategy; Installation of two AFFRA-type units could be considered somewhat experimental and therefore a useful demonstration.

1. Grand Forks
2. Manitoba location

8. Stage-Damage Curves

Stage-damage curves allow estimates of damages for various classes of structures and levels of inundation to be made. Hence, the benefits of mitigation measures can be calculated and alternatives compared. At present the curves in use in the Red River valley are the 1983 ECOS curves based on the 1979 flood in Manitoba and the 1992 FEMA curves based on flooding throughout the USA. The 1997 flood damaged a significant number of structures in the valley. There is therefore an opportunity to create new basin specific curves, at least for residential properties.

Implementation Strategy:

1. Determine level of interest in emergency management agencies
2. Assemble damage particulars for 1997 to determine if a basin wide approach is feasible
3. Seek cost-sharing partners

Improved management of the floodplain requires more coordinated and integrated decision-making, using models and other decision support tools. Agency and public interaction with the IJC and the International Red River Basin Task Force has clearly identified the need to improve flood forecasting in the Red River basin. This can be accomplished by improving the present hydrologic and hydraulic models for the basin. Other potential requirements for new models also exist; these would only be pursued if the Task Force determines that they are needed.

A word about nomenclature . In the context of this study plan, tools can be thought of as a suite of models, as in a decision support system; a means of presenting modeling results, as in a geographic information system; or a derived table of values or correlation. While models can be considered as numerical or physical, the Tools Subgroup has not considered developing physical models.

The work of the Tools Subgroup will depend on interaction with the Strategies Subgroup, particularly in identifying modeling needs as some of the models and other tools could be used in a planning tool by the Strategies Subgroup. The work of the Tools Subgroup will also require careful interaction with the Database Subgroup. Data assembled by that Subgroup will be required as input to new models. Also new data for modeling would be contributed to the database.

ANTICIPATED RESULTS

The projects defined in this section have different degrees of certainty and completeness. Depending on the final work plan, the Tools Subgroup may have to add additional members and increase cross-membership with other subgroups to ensure that all needs are met.

The principal activities of the Tools subgroup were identified during a November workshop aimed at examining hydrologic and hydraulic modeling needs and the related data requirements. Since that time other possible modeling or tools requirements have been identified.

In a very simplistic sense, priorities for the US portion of the basin are improvements to hydrologic models and for the Canadian portion are improvements to the hydraulic models. These priorities are tempered by the availability of funding in each country.

The purpose of this document is to summarize the Tools Plan of Study and to identify the means by which the plan would be implemented. An underlying strategy is to have the entire Tools Subgroup manage in Phase I some immediate tasks that would be funded largely with Canadian funds with the idea that complementary Phase II US projects could be added on later.

Models developed as part of this study can form an important legacy if they meet the needs of operational agencies. For that reason, every effort will be made to identify key user agencies, build in agency requirements, and to ensure models can be run in a pc-based environment.

STUDY COMPONENTS

1. Hydrologic Models

Although the current flood forecast models did a reasonably good job of forecasting flood volumes, it should be noted that the 1997 flood was relatively simple from a hydrologic perspective. A number of improvements are needed in the short term and over a longer time period. In addition there is a need to improve our understanding of hydrological processes in the basin through sub-basin scale studies. These studies would allow a better understanding of effects of land use change, drainage, cultivation practices, and the role of wetlands. Needs include:

Real Time Flood Forecasting

• Updated present forecast models to include 1996 and 1997 data and to enhance soil moisture components
• Improved infiltration-runoff relations
• Regionalized models to better handle distributed precipitation patterns
• Hydrometric and climate data for forecasting and model verification
• New models based on lumped and, perhaps, distributed inputs
• Improved algorithms and remotely sensed products to support forecasts

Sub-basin Studies

• Identify ‘data-rich’ sub-basins that are representative of the Red River valley
• Run distributed hydrologic models with a time series of alternate landscapes to determine effects of land use on water yield
• Identify methodologies for scaling studies up

Implementation Strategy: Complete preliminary work so that projects can be implemented as funding becomes available.

1. Continue agency modifications to existing models.
2. Identify locations for sub-basin scale modeling studies.
3. Initiate additional work as funding becomes available.

2. Hydraulic Models

The need for hydraulic models that could be used to route forecasted flood volumes in the Red River valley and, in particular, handle overland flow was identified early in the study. The purposes of such models fall into two categories: real-time flood forecasting, and planning and design. Identified needs are:

Real Time Flood Forecasting

• Determine flood levels and timing of peaks
• Determine hydrograph shape and inundation
• Account for overland flows
• Conduct backwater calculations at critical locations
• Incorporate infrastructure changes such as breaches and blow outs
• Carry out what if analyses

Planning and Design

• Post flood analyses for infrastructure evaluation and design
• Determine effects of flood operations
• Analyze structural and non-structural peak shaving proposals
• Conduct what if and sensitivity analyses
• Define data and monitoring requirements
• Evaluate the aerial extent and volume of the 1826 flood

As part of the modeling, a GIS post-processor would be developed so that results can be incorporated into future decision support systems.

The development of ‘quick pass’ one dimensional unsteady flow models from Emerson to the Floodway inlet by consultants for the Manitoba Water Commission and by Environment Canada for the Task Force has shown that many requirements can be met by such modeling. It is assumed that a fully developed model could be used to identify needs for two dimensional models. Wind effects, in particular, are a concern.

Currently the elevations of Manitoba highways, railways and a few municipal roads are known to a high degree of accuracy. Bridge openings and head losses in 1997 are also documented. The sizes of drains and culverts, while available, have not been entered into the models. The models have shown that there are problems with the existing digital elevation data in parts of the basin – this must be improved if detailed analyses of certain key locations are to be carried out. There is also a need to verify the bathymetry of the River at key locations. Obtaining the available Radarsat imagery for the flood would be very useful for model verification.

Implementation Strategy:

• Phase 1: Proceed with developing a detailed one dimensional model for the portion of the basin from Grand Forks to the Red River delta. The model would include a GIS post processor.
• Use consultant contract with clearly defined milestones

Flood strategies will cover components of the emergency planning cycle such as preparedness, response, recovery, and flood damage reduction. The strategies will also address specific technical, environmental and social topics.

STUDY COMPONENTS

A number of issues have been identified by Commissioners, the Task Force and by the public. These are listed and described below. The listing remains to be further defined. A number of the issues relate to recommendations in the Interim Report and may need no further Task Force effort, other than to monitor the success of the governments in implementing them. In the further refinement of the plan of study, the list may be modified to ensure that the Task Force covers the issues of most concern to the public and of most importance to future flood preparedness.

1. Water Management

Water management issues were of much concern in the public consultations that have been held. The Plan of Study proposes looking at the issue through three types of studies: land use including wetland issues, water retention, and water management strategies. Work will be undertaken that answers the following questions.

1. How much water needs to be stored to reduce the flood crests at various locations in the valley to below design standards (100-year flood, 1997 flood, 1826 flood)?
2. Is there enough retention capacity within the critical parts of basin to achieve that objective, using storage dams, on-land waffle or micro storage and wetland expansion?
3. If there were enough capacity, what would be the cost?
4. Can potential and existing water retention sites be regulated to reduce the peak flows?
5. Can agricultural drainage practices reduce quick runoffs and high peak flows?
6. If there is not enough capacity to affect the floods of 1997 or larger, is there a case for using these water retention alternatives to reduce the peak of smaller floods?
7. What are the costs be for different volumes of retention? What would be the disbenefits and benefits, including compensating environmental and other benefits?
8. What are the effects of water retention on downstream interests during low flow or normal flow years?

The subgroup would review existing studies in the Red River basin and relevant literature, use existing models, and conduct their own investigations as required. The work would be done in consultation with the Data and Tools Subgroups. Studies would be conducted that document:

1. Current land use practices, especially agricultural drainage, and their effect on peak flows, and the potential for slower drainage or temporary on-farm water storage to reduce peak flows. If there were sufficient potential, the study would determine the economic costs of altering the existing land-use practices.
2. Wetland expansion to evaluate the potential for flood peak reduction
3. Potential reservoir storage and the management of such storage along with on-farm micro and waffle storage to reduce flood peaks.
4. Previous, current and proposed projects, including location and size of impoundments.
5. The potential benefits and costs, including downstream consequences, of water retention strategies.

Implementation Strategy

1. Conduct studies of wetlands for water retention possibilities.
2. Questions 1,2,4,5 to be answered through models developed by the Tools group. Based on the answers to these questions, the other questions will be addressed.
3. Update all existing data and costs on storage.

2. Floodplain Management

Floodplain management policies throughout the basin and how well they work need to be better understood. A study should be undertaken that explains the floodplain regulatory and management policies of agencies, such as Manitoba Natural Resources and FEMA, the incentives and disincentives for appropriate behaviour the policies promote, and how the floodplain management regime might be improved.

Tools Subgroup models could determine whether current regulatory standards are adequate – in Manitoba the 1997 flood plus 2 feet, in the US the 100-year floodplain. Issues include:

1. In Manitoba, is the approach to meeting the new 1997 plus two foot standard through the use of community and home dikes and pads creating potential flood problems?
2. In Manitoba, are there financial obstacles hindering or prohibiting residents from meeting the new standards?
3. Is there a case for removing more homes from high-risk areas?
4. In Minnesota and North Dakota, what are the factors that have reduced the acquisition of national flood insurance and what steps need to be taken to increase acquisition?
5. Does floodplain mapping need updating as the basis for enforcement or development of floodplain policies? (Mapping issue likely to be addressed by Data Subgroup.)
6. Can we develop stage-damage curves based on 1997 for use in project planning?

The outcome from the investigations would be:

1. Understanding the strengths and weaknesses of the basin’s floodplain management.
2. Recommendations on how to strengthen the floodplain planning regime.

Implementation Strategy:

1. Describe the floodplain management structure within the various jurisdictions and areas of responsibility
2. Provide a critical review of the policies and programs.

Data Subgroup to deal with question 6 on stage-damage curves.

3. Pembina River Flooding

The negative transboundary impacts of certain dikes and drainage practices have been the subject of controversy in the lower Pembina basin. However, in the past there have been studies showing benefits from flood control to both sides. The economic considerations used in coming to a negative conclusion about the proposed projects are now dated. Before examining the specifics of dikes and drainage, the earlier proposals need to be revisited and examined in light of water demands from new crops, such as potatoes, and for domestic and industrial water supply. Other proposals for a boundary floodway may also need to be re-examined.

To help resolve the long standing border issue studies would be conducted to address issues, such as:

1. To what extent has diking and drainage on both sides of the border contributed to flooding in the lower Pembina River?
2. Is there a basis for revisiting previous proposals for resolving the issue?
3. Are there other alternatives that might be explored?
4. What are the positive and negative environmental and other impacts of the alternatives?

At a minimum the work could result in:

1. Agreement on the facts about the causes and responsibilities for local flooding.
2. Agreement on a process for resolution of the issue.
3. Recommendations on how the issue could be resolved.

Implementation Strategy:

1. Review old studies (Pemblier Dam, two dam proposal) and revise economic feasibility of the projects to account for changing demands for water for agriculture (irrigation of new crops such as potatoes), for industrial use and municipal water supply.
2. If feasible, review possible negative consequences, particularly environmental impacts.
3. Consult with the local organizations and groups.

Tools group to model diking and drainage in the lower basin.

4. Emergency Measures–Transboundary Cooperation

Transboundary emergency preparedness is important for cooperation and sense of unity in the basin. The press and public have no patience for failures in this area. Recommendation 13 of the Interim Report called for a regionally specific agreement for the Red River for transboundary emergency measures cooperation. Secretary of State Albright and Foreign Affairs Minister Axworthy requested the IJC to develop a framework for a flood emergency agreement for the Red River basin.

Emergency Preparedness Canada (EPC) and Federal Emergency Management Agency (FEMA) have the authority to deal with transboundary emergency cooperation and will be approached regarding new arrangements.

The Strategies Subgroup will, with the cooperation of the relevant federal and state/provincial agencies, determine how transboundary flood emergency cooperation can be improved among the two federal governments, two states and the province and what new agreements or institutional arrangements are required in an international agreement? This work should lead to a Canada-US agreement on transboundary emergency cooperation for Red River flooding.

Implementation Strategy: Monitor discussions among federal state and provincial agencies. If required, based on discussions with local, state, provincial and federal emergency measures agencies, prepare a discussion paper on basin requirements for a transboundary emergency measures agreements.

5. Red River Forecasting Liaison Committee

Recommendation 15 of the Interim Report calls for a basin-wide flood forecasting committee patterned on the Souris River Flood Forecasting Liaison Committee. Secretary of State Albright and Foreign Minister Axworthy requested the IJC to define the way in which the proposed Red River flood forecasting committee would operate.

The Souris River Flood Forecasting Liaison Committee can serve as the model for the Red River. Information on how it works and any difficulties will be considered in recommending a structure for the Red River Forecasting Liaison Committee.

Implementation Strategy: Work with relevant agencies to provide recommendations on how such a committee should operate

6. Flood Design Standard

Political leaders must decide on the level of risk to be tolerated in the design standards for urban and rural areas. The Task Force can help provide the information to help inform the decisions, e.g. the likely repeat of the floods on scale of or larger than 1997 and the consequences of such floods.

A major issue on the Canadian side is the vulnerability of Winnipeg. There are a number of issues concerning the risks faced by the city – floodway capacity and operation, primary and secondary dikes,

Should a greater degree of safety be built into standards adopted for areas where the risk of failure can have catastrophic consequences, particularly when there are records of even greater floods (1826) than experienced in 1997? Through risk analysis and exploration of long-term flood forecasting (note Geological Survey of Canada paleo-hydrology project for the Red River to determine high flows), the subgroup will review the case for revising current flood design standards.

Regulatory standard issues are dealt with under issue #2, Floodplain Management.

Implementation Strategy:

1. Document design standard approaches in different jurisdictions within the basin and determine whether generic principles for looking at risk within the basin can be proposed.
2. Tools Subgroup to model floods of greater peak than 1997.
3. Conduct a risk analysis for the city of Winnipeg.

7. Lake Traverse Biota Transfer

Is there a hydraulic connection and transfer of biota between the Red and Mississippi basins through Lake Traverse and, if so, under what conditions? The subgroup will undertake engineering studies to review the operation at Lake Traverse and Big Stone Lakes along with the role played by associated works. Following this review, recommendations will be made on what can be reasonably implemented to minimize or eliminate exchanges of water between the two basins during future flood events.

The work envisioned would be on the possibility of a hydraulic connection. It would not address biota transfers, only whether conditions could exist in which biota transfer is possible.

Implementation Strategy: Consider the conditions under which there might be a hydraulic connection and the impacts (positive and negative) of acting to avoid such a connection.

8. Institutional Arrangements

One of the main objectives of the Task Force is to facilitate integrated flood management in the basin. This will require ongoing institutional arrangements.

The Strategies Subgroup will review the role of current and proposed organizations and evaluate the roles they might have in future integrated flood planning. The review will result in recommendations as to what institutional arrangements should be established to carry on basin-wide transboundary integrated flood planning and other water management issues.

Implementation Strategy: Prepare a discussion paper on institutional arrangements that would focus on concepts and parameters rather than on current or proposed institutional arrangements.

9. Water Quality – Lake Winnipeg

Flooding may result in downstream water quality problems. Work will be initiated to see whether Red River flooding causes such problems and whether they are serious. Investigations will determine what substances are the greatest risk and whether the source of the substances can be traced within the basin. Possible nutrient loading problems from floods will be explored. The outcome will be a determination of the concentration and distribution of hazardous substances as the result of Red River flooding and recommendations on how to deal hazardous substances that affect water quality.

Manitoba has a significant interest in the deposition of hazardous material in Lake Winnipeg because of the 1997 flood. Fishermen are concerned but they do not have sufficient information to know whether the fish stocks are threatened.

Implementation Strategy:

1. Department of Fisheries and Oceans to collect and analyze Lake Winnipeg samples.
2. The Red River Pollution Board to review the results.
3. Using the findings of the study, review the need to do work on spill response.
4. Based on the study, determine whether storage and use of hazardous material policy needs to be changed within the basin.

10. Groundwater

To what extent does flooding present a threat to water quality in aquifers? What measures can be taken to prevent contamination of aquifers? Are these measures adequate and sufficient? Studies may be undertaken to determine whether further recommendations are needed on measures to prevent groundwater contamination (as in recommendation 38 of the Interim Report on surveying and sealing wells). One product of the studies could be a best practices guide for abandonment and construction of wells.

The states and the province have policies and programs in place to deal with wells and contamination of groundwater.

Implementation Strategy: Monitor progress of states and the province in dealing with contaminated groundwater from flooding and determine whether additional studies needed in Phase II.

11. Environmental Design and Mitigation

How can water management projects be designed to increase habitat, support wildlife and provide other environmental benefits? Studies will be undertaken to determine the need and content for environmental design recommendations for floodplain and water retention projects.

Implementation Strategy: In Phase II, prepare a compendium of best practices using Canada, American and international sources.

12. Recovery Assistance

Canada and the United States have different approaches to both individual and business disaster recovery. Are there lessons that can be learned from each other? More generally, should assistance be tied to other floodplain management objectives, such as floodproofing, insurance, or removal from areas at high risk? Residents in some areas of the floodplain feel they were flooded because of the operations of flood control works. If operations of certain works do lead to flooding for some, should there be different levels of assistance for those affected by flood operations?

The appropriate mechanics of recovery assistance and economic recovery assistance is a major undertaking that the Task Force may not be able to take on at this time. However, some assistance policy issues may be worthwhile to examine. What is the responsibility of the individual vs. the government in the disaster recovery process? Individuals and charities once provided all the assistance. Governments have come to provide a greater share, but the increasing number of disasters and cost are making governments reconsider their support. In recommending an equitable (to residents and citizens outside the basin) and effective floodplain management regime, disaster assistance is an important component. It can work to promote beneficial land use changes or help perpetuate an undesirable situation.

Implementation Strategy: Prepare a "think piece" on recovery assistance for flood prone areas of the Red River basin.