According to BlackRock, the world’s largest asset manager, water stress is a hidden investment risk in many portfolios. The firm’s analysts claim that within a decade, much of the world will lie within areas of high water stress (areas where demand exceeds supply). Most of Canada does not fall within these forecast high water stress areas, however some parts of the country are none-the-less experiencing water woes. In southwest Nova Scotia, for example, wells have been going dry since 2016 and when your well goes dry, daily life becomes challenging at best. John Drage is a hydrogeologist with the province who developed a real-time monitoring network to track the water levels in dug wells in Nova Scotia. We asked Mr. Drage a few questions about the water problems in some parts of the province.
What do you do as a hydrogeologist for the province?
As a hydrogeologist with the Nova Scotia Geological Survey I provide scientific advice for managing and protecting Nova Scotia’s groundwater.
When did the province start having water shortages or has this always been a problem?
The most severe recent water shortage problem in the province occurred in 2016. In Southwest Nova Scotia, 2016 was the driest summer (i.e., June/July/August) on record since 1880. However, there have been similar dry summers in the past. For example, if we look at the precipitation data for Yarmouth, after the summer of 2016 (87 mm total rainfall), the next three driest summers on record happened in 1934 (111 mm), 1882 (117 mm) and 1894 (130 mm).
Has it become a chronic problem or more severe lately?
If we look at the rainfall record for Yarmouth again, it shows that three of the top 10 driest summers on record happened in the last 20 years (2016, 2008 and 2018). It also shows that two of the wettest summers on record happened in the last 20 years (2006 and 2009). This suggests that we may be seeing more extreme weather events (droughts and floods) due to climate change, as predicted by climate scientists.
Are there parts of the province where it is worse?
Southwest Nova Scotia experienced the driest conditions across the province in 2016. During that summer, Yarmouth received 32% of its normal rainfall. 2018 was also a drier than normal summer during which Southwest Nova Scotia also experienced the driest conditions across the province. Yarmouth and Shelburne received about 50% of their normal summer rainfall in 2018.
What is causing the problem? When can we expect it to improve?
Climate scientists tell us that climate change will cause more frequent extreme weather events in the future, such as droughts and floods. For Nova Scotia, the climate is predicted to become hotter and wetter. However, it has also been predicted that we will see lower groundwater levels in the summer because, although it will be wetter, it will also be warmer which will cause more evapotranspiration and, therefore, there will be less water available to seep into the ground to recharge aquifers.
Is lack of snow a contributing factor?
Snow melt helps recharge aquifers. If we have less snow than normal, then there is less snow melt contribution to aquifer recharge in the spring.
What can homeowners do if they have water shortage problems (or if their area is experiencing drought)?
There are a number of short-term and long-term solutions that a homeowner can use to help mitigate water shortage problems. For example, short-term solutions include water conservation and staggering daily water use. Long-term solutions include installing a water
storage tank, lowering the pump’s intake in a well (if possible), deepening a well, or replacing a shallow dug well with a deep drilled well. The Province has a fact sheet that provides advice to well owners for solving water shortage problems (see page 59 here: https://novascotia.ca/nse/water/docs/Drop_on_Water_English.pdf). Homeowners should also check with their municipality to see if they offer loans for upgrading water supplies.
Is the province or some municipalities doing something to address the issue?
The Province and municipalities have taken action to assist well owners who are experiencing water shortage problems. The Province passed legislation in 2016 to enable municipalities to offer loans to homeowners for upgrading their water supply, for example by replacing a shallow dug well with a deep drilled well. There are now seven municipalities in Nova Scotia that currently offer these loans, including the Municipality of Yarmouth (https://www.district.yarmouth.ns.ca/index.php/municipal-operations/municipal-programs- services/264-water-supply-upgrade-lending-program-by-law). In addition, the Nova Scotia Geological Survey has developed a real-time dug well monitoring network for tracking water levels in shallow aquifers during drought conditions (https://tinyurl.com/NS-Realtime-Well- Water-Network). The Geological Survey also publishes a map that shows drought risk to private wells across the province (https://fletcher.novascotia.ca/DNRViewer/?viewer=DroughtIndex).
What is the water table? Is it possible to deplete it or bring it dangerously low? Are the water tables in an area connected? Can the use of one individual/business/ community affect the water available to another individual/business/community? Are water tables in the province low?
The water table is the water surface of a shallow unconfined aquifer. It is the water level you see when you look in a shallow water well. In Nova Scotia the water table is usually found within about 5 m of the ground surface, but it can be deeper in areas with high topography. The water table is usually a continuous surface in a given area; it mimics the topography so that the water table elevation is high in high elevation areas and lower in lowlands. Groundwater is always moving; it flows from highlands towards lowlands. It is possible to lower the water table by pumping groundwater from a well. The more groundwater that is pumped, the more the water table drops and the larger the area of influence becomes. Pumping from one well can lower the water level in another well if the wells are close enough together; this is called well interference. The water table undergoes regular seasonal variations. It is usually high in the winter and spring, drops in the summer when there is less rainfall, and then recovers in the fall when rainfall increases again. Water table levels are tracked in Nova Scotia with a real-time dug well monitoring network (https://tinyurl.com/NS-Realtime-Well-Water-Network ). Currently (July 11, 2020), water levels are normal in Cape Breton but on the mainland they are on average about 1 m lower than they were at the same time last year.
Does protecting wetlands help? Are there other ways that land use can make the problem better or worse?
Wetlands play an important role in the hydrologic cycle because they help regulate water quality and quantity. Their natural capacity to store water can help reduce flooding and provide recharge to aquifers. Because of the important role that wetlands play in the environment, the Province has a policy to protect them (https://novascotia.ca/nse/wetland/conservation.policy.asp). Many land use activities have the potential to affect the hydrologic cycle. For example, installing impervious surfaces (e.g., paved parking lots, roads) can increase runoff and reduce aquifer recharge. There are techniques available to help maintain natural hydrology, such as the use of Low Impact Development stormwater management, which reduces the impacts of increased runoff and stormwater pollution by managing runoff close to its source.