Drought Resilience
We are fortunate to have two mountain-fed rivers flowing into Calgary, but in the future, our rivers and water supply will face pressures from:
- a growing population,
- limits on how much water we can draw from the river, and
- the effects of a changing climate where droughts will be more common.
Building resilience to drought today means Calgary will be better prepared for climate change and be able to protect the rivers we all rely on.
As a drought-resilient city, Calgary, along with its people, ecosystems, and businesses, is prepared to withstand, recover from, and adapt to the impacts of drought.
Calgary’s Drought Resilience Plan
In the face of increasing drought risk due to climate change, The City is committed to working toward a drought-resilient city for all Calgarians.
Drought resilience means that people, ecosystems, and businesses are prepared to withstand and recover from the impacts of prolonged periods of dry conditions and water shortages.
The Drought Resilience Plan sets the long-term direction for proactive drought resilience measures and identifies the key actions we need to take now to adapt to the hazard of drought.
Goals:
These goals are premised on the guiding principles of climate resilience, water stewardship, equity & inclusion and innovation.
The impacts of drought
Some impacts, like reduced water for drinking and irrigation, are more obvious. Others are harder to see but still leave profound and lasting effects.
The following ‘impacts’ highlight the breadth of issues caused by drought and the ways drought can increase the risk of other hazards, including floods, heatwaves, and wildfires.
Water supply impacts
Drought reduces the water available to provide for Calgary’s core infrastructure: clean water for drinking, firefighting, irrigation, and industry. It can lead to:
- impacts on water treatment & supply,
- restrictions on water use,
- reduced quality of green space in urban areas, and
- interruptions to community services.
Ecological impacts
Drought reduces the water available for natural spaces and ecosystems to thrive. This can mean:
- loss of habitat and biodiversity,
- increased susceptibility to disease, pests, and invasive species,
- reduced water quality,
- stress to fish and wildlife,
- increased incidence and severity of wildfires, and
- increased severity of flooding.
Economic impacts
Drought reduces the water available for irrigation, industry, and recreation.
These issues, compounded by the unpredictability and instability of multi-year drought conditions, can lead to:
- interruptions to business,
- impacts on farmers and food prices,
- loss in recreation and tourism,
- increased cost of municipal services, and
- impacts on large-scale commercial and industrial water users.
Social impacts
Drought has a direct impact on the physical and mental health of citizens.
As a regional phenomenon, coordination across jurisdictions adds another layer of complexity. Some social impacts include:
- mental and physical stress,
- air quality impacts from increased dust and pollutants,
- reduction/modification of recreation opportunities,
- reduced quality of important cultural landscapes,
- impacts on food security, and
- unequal distribution of impacts between users.
Frequently asked questions
Drought - General
What is drought?
A drought is when there is less water available over a large physical area for a long period of time. It happens when precipitation (for example, rain or snow), river flow, and ground water are below average levels.
Drought can generally be described as a prolonged period of dry weather that depletes water resources. Water resources may include:
- natural sources such as rivers, streams, lakes, wetlands, and groundwater,
- human-made storage such as reservoirs and dugouts, and
- soil moisture.
For The City of Calgary, drought occurs when the water required for municipal supply, irrigation, and minimum environmental flows diminishes below The City drought triggers and supporting indicators.
Unlike floods, which can happen very quickly, droughts develop slowly over time. A drought can last anywhere from weeks to months and can evolve into multi-year droughts if the region is consistently not getting enough moisture.
Calgary is most at risk of experiencing a drought from mid-July to the end of September.
How will climate change impact drought risk in Calgary?
The reason why drought is a top climate hazard for Calgary is because regional warming trends will result in seasonal shifts in the type and timing of precipitation. This means that there will be less water in the rivers when we need it most – during our hotter, drier, and longer summers.
These impacts are compounded by growth and an increasing development footprint – as you can see on the right - which replaces our natural landscapes with, typically, less drought resilient landscape types that require irrigation.
In addition to impacts on our drinking water supply and local agriculture, droughts can cause:
- negative health impacts to plants, wildlife, wetlands, forests, parks, open spaces, recreational facilities, and private yards,
- drying out of forests and grasslands and an increase in the risk of wildfires, which impact both local air quality and water quality, and
- increased pests and disease outbreaks (for example pine beetles) in trees and plants. Lack of water can stress trees, limiting their ability to react to these attacks.
How does drought resilience connect to Calgary’s overall water security?
The City of Calgary defines water security as having enough water for human well-being, ecosystem resilience, and economic activity now and for future generations. Calgary’s Water Security Framework outlines The City’s top risks to water security (climate change, population growth, and water license limits), key initiatives underway, and priority actions that address questions of future long-term water security out to the year 2100. The creation of the Drought Resilience Plan is a key action identified in this strategy.
What has The City done to date to increase our resilience to drought?
The City has taken several proactive steps to explore ways to increase our water storage and manage our demand to ensure we have a year-round reliable water supply.
For example, the addition of higher gates at the Glenmore Dam doubles the storage of the reservoir, which not only increases flood protection but also improves our climate resilience to future droughts so we can store more water in the winter when flows on the Elbow River are at their lowest.
Also, significant progress has been made to help reduce our water demand by nearly 30 per cent despite a growing population. This includes investments in leak detection, water main replacements, water metering, and the adoption of low-flow toilets and faucets.
How important is glacial melt to our water supply in Calgary?
Glacial melt is important. On average, glacier melt makes up approximately three per cent of Calgary’s annual river runoff with most of our water supply coming from precipitation (snowmelt and rain).
However, if we were to experience a drought extending into August, when precipitation is at its lowest, glacial melt would contribute 8-20 per cent of our water supply when there isn’t as much precipitation to rely on.
With rising temperatures due to climate change, glaciers will continue to shrink, meaning we won’t have the same steady supply in our rivers to sustain us over the driest months of the year.
Drought Resilience Plan
Why is having a Drought Resilience Plan important? And why now?
Drought has received renewed attention over the last decade as climate change and urban growth reshape supply and demand in the Bow River watershed.
History shows that our region is prone to prolonged, severe droughts which will be intensified by climate change in the future. A multi-year drought impacting Calgary is one of our city’s top climate hazards, and improved climate modelling and risk analysis has provided new technical knowledge of how droughts will impact Calgary, and strategies needed to mitigate those impacts. This plan is timely to demonstrate accelerated action for climate adaptation.
Persistent water scarcity can erode investor confidence in a city's economic prospects, potentially deterring investment in both local businesses and infrastructure projects. Implementing the holistic suite of strategies for drought resilience is critical for supporting long-term growth and city building in a semi-arid and drought-prone region.
How will this plan impact Calgarians?
To build drought resilience, some of the strategies we are considering need the participation of all Calgarians and businesses to reduce how much water we need and use.
Why is demand management a priority action?
Demand Management–a broad term for managing how much water we use as a municipality–is a priority goal within the Drought Resilience Plan. Maintaining a thriving city and economy in a drought-prone location requires a continuously evolving relationship with water and climate change through an update to the current City of Calgary Water Efficiency Plan. This is foundational work and connects to the other goals from the water supply, readiness and response, ecosystem, and people perspectives.
Key actions include updating the targets and actions in our Water Efficiency Plan, addressing the potential financial impacts of drought, and updating the water restrictions section within the Water Utility Bylaw. Enacting water restrictions this summer and fall has offered an opportunity to have real-time data and customer experiences to draw on.
What is the current per capita water consumption in Calgary and how does this compare to other municipalities?
In Calgary, our 2022 demand was 351 litres per person per day (lpcd), and our net residential consumption was 174 lpcd, which includes both single family and multifamily.
The City is part of a national benchmarking initiative for water utility performance indicators. This reporting shows that among other Canadian municipalities, Calgary ranks in the median for residential daily consumption.
How does the Drought Resilience Plan connect to the Climate Strategy and its implementation?
Calgary’s Climate Strategy identifies drought as one of Calgary’s eight main climate hazards, and the adaptation action plan directs the development of the Drought Resilience Plan to identify pathways and strategies to address drought-related impacts.
The Drought Resilience Plan’s implementation schedule lists the alignments between the drought strategic actions and the climate strategy adaptation theme areas of People, Built Infrastructure, Natural Infrastructure and Water.
How does the Drought Resilience Plan connect to the City Building Program?
The Drought Resilience Plan articulates the intersections of drought and city building, and the impacts of growth and urban form on water uses. Through the Land Use Bylaw renewal and City Building program, an opportunity is presented to review and update landscape regulations to encourage or require more native and drought-tolerant plant species and other resilient landscaping features, that will support better outcomes for drought resilience on private landscapes.
How does this plan address the risk of increased invasive species due to drought?
The plan identifies in-stream flows (meaning, the quantity, timing, and quality of water flow required to sustain freshwater ecosystems) as one of the systems with the highest vulnerability to drought. Flows, water quality, the potential for reduced biodiversity, and the influx of invasive species were the most vulnerable components.
The Healthy Landscape goal looks at strategies that protect our aquatic ecosystem in low flow and drought conditions, as well as ensuring our built and restored landscapes use drought-tolerant species that ensure they can thrive during drought and minimize potential disturbance from other invasive species.
Is there water reuse taking place in Calgary?
The City of Calgary already assumes responsibility for authorizing water reuse projects on a case-by-case basis, including the use of reclaimed water from our wastewater treatment plant for a key industrial customer.
The City also irrigates some parks around Calgary with non-potable water. Currently, seven large sites are using either untreated river water (Bowness Park, Prince's Island, Baker Park), well water (Valley View) or storm water from run off (Inverness Storm Pond, Nose Creek Recreation Centre).