PUBLISHED: 17 December 2013

Flood Mitigation: Understanding Groundwater Flooding

What is groundwater flooding? 

Groundwater flooding is caused by high rainfall and river water levels that result in basement and surface flooding. In the event of heavy rainfall, underground aquifers (areas with permeable rock that water can pass through) are inundated and filled possibly resulting in flooding[1]. The damage to property and infrastructure caused by groundwater flooding can be extensive and detrimental to the integrity of buildings. 

How does this option help to mitigate the impacts of a flood? 

Groundwater flooding can result in damage to basements due to underground water tables rising above minimum basement grades further entering buildings through seepage and cracks in foundation. Monitoring and managing this source of flood water is important to mitigate the impacts of a flood. Modelling groundwater flooding and mapping areas at risk of groundwater flooding are important mitigation methods to determine potential impacts and subsequent responses to flooding. Having this technology and ability to monitor groundwater levels is important to managing water and responding to flood events [2]

What understanding of groundwater flooding is already in place in Alberta?

At present, Alberta does not have extensive groundwater monitoring, mapping or modelling technology that identifies high groundwater flood-risk areas. Post-flood analysis has shown that groundwater levels were abnormally high weeks before the flood event further indicating the close relationship between groundwater, surface water and flood water[3]. Improving groundwater management and knowledge will be important for future flood preparedness and mitigation measures. 

What level of government is responsible?

The government of Alberta is responsible for groundwater management and regulations associated with groundwater. From a legislative perspective, the Water Act prescribes licenses while the Environmental Protection and Enhancement Act ensures that groundwater quality is maintained and protected[4]. From a policy perspective, the Water for Life Strategy, Water Management Plans, Land-Use Framework and Water Conservation and Allocation for Oilfield Injection all address groundwater and the need to protect this important resource[5]. Research and decision-making on groundwater will continue to be important to understanding flooding and other areas such as coalbed methane development. 

Does this policy account for differences between jurisdictions? 

Understanding the role groundwater plays in overall watershed health and water systems requires specific jurisdictions to be considered before understanding the larger picture. The Land-Use Framework attempts to establish this understanding by initiating groundwater management through the development of a series of Groundwater Management Frameworks[6], however, this work has yet to be completed.

What is the scale and boundary of this policy? 

Policies and legislation addressing groundwater resources in Alberta apply at the provincial level. Research on groundwater, however, is done at the regional level where specific information can be gained. Groundwater research and policies apply only in Alberta.  

What are the enforcement measures?

Specific enforcement measures related to groundwater do not currently exist in Alberta, however, directives protect groundwater resources especially in the process of energy extraction. For example the Energy Resources Conservation Board, now the Alberta Energy Regulator, has released numerous directives aimed at coalbed methane production to protect groundwater resources[7].  These include; Directive 009 where cement casing is required, Directive 035 where baseline water well testing is required, Directive 044 that requires surveillance, sampling and analysis of water production, and Directive 027 that addresses shallow fracturing operations[8]

What are the effects on the surrounding environment and watershed? 

Groundwater has an important role to play in overall watershed and ecosystem health, therefore, understanding this valuable resource is integral to determining what role aquifers play in flooding. This interconnection between surface water and groundwater flooding requires further research to determine environmental and watershed impacts. 

Would understanding groundwater flooding help in a drought? 

Yes, having a greater understanding of the connection between groundwater and surface water would help us to manage drought conditions. Groundwater is important to drought management because it can provide an alternative source of water, indicate drought conditions due to lower water levels in lakes and rivers, and determine impacts on water quality that can also harm aquatic species[9].  

[1] ‘Short Animation of Groundwater Flooding.” UK Environment Agency. Accessed December 16, 2013. 

[2] “Groundwater Flooding.” British Geological Survey. Accessed December 16, 2013. 

[3] Semeniuk, Ivan. “Satellite data hinted at Alberta floods weeks ago.” Published June 25 2013. Accessed December 16, 2013.

[4] “Regulation and Policy.” Alberta Environment and Sustainable Resource Development. Accessed March 24, 2014. 

[5] Ibid. 

[6] Ibid. 

[7] “Regulation and Policy.” Alberta Environment and Sustainable Resource Development. Accessed March 24, 2014. 

[8] Ibid. 

[9] “Groundwater and drought.” USGS Groundwater Information. Last modified March 6, 2014. Accessed March 24, 2014.