Where our water comes from
The debate on high-capacity wells for irrigation goes back to 2001 when, following a particularly dry year, the province was flooded with applications for irrigation wells.
|Read about the recent debate on high-capacity wells here.|
A moratorium on high-capacity wells for irrigation was put in place in February 2002. The government was concerned about the impact of a large number of high-capacity wells, and put the moratorium on to give itself time to study the issue.
Almost all water used in the province — whether for homes, industry or agriculture — comes from wells. The water in the wells is known as groundwater, a reservoir of water under the surface. This water, however, does not just lie still underground. It bubbles up in springs and flows into stream beds. Groundwater is the source of two thirds of the flow of water in the Island’s rivers. In dry summer months, it can be the source of as much as 100 per cent of the freshwater.
Every drop of water pulled out of a well is water that would otherwise have eventually flowed into an Island stream.
While no new wells have been dug for irrigation since 2002, there remain 12 to 15 wells that were grandfathered in. It is also worth noting the moratorium applies only to irrigation. All along, applications have been accepted for municipalities, industries such as food processing, and livestock farmers.
A new water extraction policy
In 2013, the provincial government made a big change to its policy for the approval of high-capacity wells.
Previously, the province calculated the impact on water resources by recharge rate, basically the amount of rainfall absorbed every year into groundwater. The new policy centres on baseflow as the central measurement, the water in a stream that comes from groundwater. This is typically measured as the lowest level in a stream over the course of the year.
The new policy says water extraction should not be permitted to reduce the baseflow in the main branch of streams by more than 35 per cent.
The change in policy has led to some confusion in the debate, with some groups placing a heavy emphasis on recharge rates to make their point, and others emphasizing baseflow. A close reading of the province’s Water Extraction Permitting Policy shows, for practical purposes, the two are directly related. It is recharge, the rain that falls and percolates into groundwater, that maintains baseflow. For calculating water available across the whole province, the province uses recharge rate for the calculation.
Not all precipitation makes it into the groundwater. Some evaporates or runs off the surface into salt water. Some is drawn up by plants.
The province calculates 2 billion m3 of rain and melted snow per year does make it into the groundwater, which makes 700 million m3 of water available residential, industrial and agricultural use under the new policy. Currently about seven per cent of that, 140 million m3, is being used.
Managing the water resource is not as simple, however, as looking at the water available province-wide.
There are more than 250 watersheds on P.E.I., each with its own characteristics - different rainfall, different flow rates into streams - and each with its own current load of high-capacity wells. Some watersheds, such as the upper Winter River, which supplies Charlottetown, are already tapped beyond the current allowable provincial limits. Others are untouched.
Sustainable development of water resources requires attention being paid to the impact on the individual watershed. No one is suggesting the upper Winter River watershed could be a resource for irrigation.
Generally, the province’s policy provides plenty of room for more high-capacity wells to be dug, with the exception of wells for irrigation, where the 2002 moratorium still applies.