Drought in Ontario? Groundwater and Surface Water Impacts and Response
Our Hydrologic Cycle is Changing
Although generally considered a water-rich province, Ontario is not immune to drought or serious water shortages. As recently as the summer of 2007 and between the years 1998 through 2002, Ontario has experienced some of the worst droughts in its history (see Ontario Droughts 1997-2007). Ontario has also begun to experience major changes in weather that diverge significantly from usual climate patterns, and that have produced consequences ranging – even within a single season – from destructive storm events to record-breaking low water events and drought.
As a result of global climate change, many experts expect these extreme weather conditions to worsen. The evidence for climate change has continued to mount in recent years, and the leading scientific organization – the Intergovernmental Panel on Climate Change (IPCC) – stated in 2007 that “Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level.” In a 2002 Special Report, “Climate Change – Is the Science Sound?,” the ECO urged Ontario’s leaders to act upon the evidence and take appropriate action to address climate change. In Part 2.1 of this Annual Report, the ECO has reviewed Ontario’s first plan to deal with climate change, The Go Green Action Plan.
Modelling work, published by the Ministry of Natural Resources (MNR) in 2007, predicted that by mid-century much of southern Ontario will receive 10 to 20 per cent less precipitation and will experience considerable warming (of two degrees Celsius or more) during the warm season. These changes indicate that the risk of summer droughts will increase over the coming years. The agriculture, forestry and fisheries sectors will face major resource management challenges in adapting to these environmental shifts.
Predictions aside, statistics show that Ontarians are already starting to experience profound water-related consequences of climate change. One data set of particular interest is the long-term record of crop water deficits in the Town of Harrow in south-western Ontario. Crop water deficit is a statistic representing an integration of the three main climate variables affecting crop productivity (i.e., precipitation, solar radiation, temperature); generally, the greater the water deficit, the lower crop productivity is as a result of insufficient or poorly timed rainfall.
This record shows how water deficits rose through the 1920s to a peak in 1930 (the hot, dry “dust bowl” years, infamous in agricultural and socio-economic history). The water deficit situation of the 30s gradually and steadily improved over the next six decades. However, from 1990 to 2005, there has been a marked upturn, comparable with the trend observed in the 1920s, and the graph shows water deficit averages for the 1995-2005 period that have not been seen since 1935.
Consequences of Changes in Hydrology
During a drought, reduced surface and groundwater source availability is of concern to all, but can expose water-dependent industries, including agriculture, horticulture and forestry, to particularly grave financial risk and hardship. For example, a drought that extended across Canada in 2001-2002 was considered a national disaster. The ECO notes that agricultural practices in some parts of the province are already starting to change. For example, farmers in Essex County, one of the most drought-prone areas, are excavating numerous small storage reservoirs, and in Haldimand-Norfolk Region, farmers have recently begun irrigating crops over a longer time span within the growing season. Irrigation systems which are more water efficient, such as drip irrigation are being developed and utilized more widely.
In addition to effects on industry, drought can have severe impacts on stream ecology. Drought can cause groundwater levels to decline and this, in turn, will cause declines in the flow of groundwater-fed streams. Evaporation combined with water taking from such streams may at some point cause otherwise perennially flowing streams to dry up, with a complete loss of aquatic life.
Last year, ECO examined the high stream flow problems, reviewing provincial responses to flooding hazards. In this article, the ECO examines how the Ontario government has begun to respond to the threat of low water conditions as a growing reality within the spectrum of the hydrologic cycle, and reviews how well the province is equipped to adapt and manage water resources under the conditions of a changing climate.
Ontario Low Water Response Plan
The changing climate and anticipated stresses on water supply point to the need for strong provincial readiness for managing drought. Drought contingency planning assesses and improves the ability of stakeholders and government to respond to low water conditions in a timely and orderly way. Essential elements of such a plan include: appropriate drought indicators; instruments and policies for water allocation and water supply; methods for public information and involvement; and conflict resolution tools. Numerous significant changes in water quantity management have been implemented in Ontario in recent years. In 2001, following the droughts of 1998 and 1999, the provincial government developed the Ontario Low Water Response (OLWR) Plan to ensure that the province would be ready to assist and support local response efforts in the event of a drought. This plan was reviewed in detail in the Supplement to the ECO’s 2001-2002 Annual Report (pages 143-148). The program operates with MNR taking a lead role and working in partnership with local stakeholders, which is normally coordinated through local conservation authorities.
The OLWR Plan defines both provincial and municipal government roles in drought contingency management. A key feature of the Plan is the existence of local Water Response Teams (WRTs). The teams include provincial and conservation authority staff, as well as representatives from local water user groups, typically involving agricultural and other rural private industry, resource management interests, First Nations and municipal government. At the provincial level, key decisions and interactions with WRTs are made by a standing committee known as the Low Water Committee.
The OLWR Plan establishes three levels of low water conditions (Levels One, Two and Three) that are based on thresholds linked to precipitation records and stream flow monitoring data, together with watershed observations. The OLWR Plan describes these indicators and the thresholds and rules for transition between levels. Very generally, the transition between levels is as follows:
- Level One (warning and voluntary water conservation) provides the first indication of potential water supply problems. While precipitation and flow indicators set the wheels in motion for declaring a Level One condition, the local CA and/or MNR staff must confirm the condition based on observations and effects in their watersheds. Once the Level One condition has been established, WRTs are brought together.
- Level Two (water conservation and restrictions on non-essential use) indicates a more serious problem. The watershed’s WRT confirms that a watershed has entered a Level Two condition.
- Level Three (conservation, water use restrictions and regulation), the most serious stage in the OLWR Plan, means that water supply is unable to meet local demands. Before declaring a Level Three condition for a particular area, the provincial Low Water Committee requires the local WRT to have:
- “clearly implemented and documented the conservation and reduction efforts taken through Level I and Level II strategies and [demonstrated] that the majority of the water users have participated in these efforts”;
- documented and adequately described “significant social, environmental and economic impacts arising from current low water conditions”; and
- provided “recommendations … on priorities for water use restrictions and other reduction activities within the watershed.”
A Level Three condition has never been declared, although indicator criteria have been frequently met. During low water periods, MNR and the conservation authorities collect, analyze and share precipitation and fow data, and report conditions on their websites.
The issuing and revising of Permits to Take Water (PTTW) by MOE under section 34 of the Ontario Water Resources Act (OWRA), is the principal mechanism available to provincial regulators to control takings of ground and surface water. Most water takings from a surface source or well in excess of 50,000 litres per day require a PTTW. Exceptions are made for water used for domestic purposes, livestock watering and firefghting. In addition, many large water takings initiated prior to 1961 were grand- parented by provisions of the OWRA that remained in force until 2008. Currently, about 6,600 PTTWs province-wide allow permit holders to take a total of about 495 trillion litres of water every year – an amount equivalent to the approximate volume of Lake Erie.
The OWRA affords numerous powers to the MOE Director to restrict water use, and to require studies to support applications to ensure that the quantities being allocated and withdrawn by users promote ecosystem protection and sustainability. During low water conditions, MOE delegates responsibility for determining the relative importance of various water uses to the WRTs. Under the OLWR Plan, water uses are classified as:
- essential (i.e., uses directly related to human health, such as drinking water, sanitation and fire protection, as well as for basic ecological functions);
- important (i.e., agricultural, industrial and commercial uses); and
- non-essential (i.e., household uses, such as swimming pools, lawn watering and car washing).
Each WRT is responsible for developing strategies to reduce water use during Level One and Level Two conditions, targeting a ten per cent reduction in water use at Level One. At Level Two, further restrictions are implemented, including invoking member municipalities’ bylaws for banning non-essential uses. Level Three is the most severe condition and when this level has been declared, the provincial agencies become formally involved in the decision-making process. If and when a Level Three condition is declared, the MOE Director can use the OWRA powers to restrict any water taking.
One of the main difficulties facing WRTs is the difficulty in obtaining data on actual amounts of water withdrawn by PTTW permit holders. At present, new requirements for monitoring of quantities of water used are being phased in under the Water Taking regulation (O. Reg. 387/04) (for the ECO's review, please see Water Taking and Transfer Regulation under the OWRA. Information on water withdrawals is vital to a WRT trying to determine how water is allocated in a watershed during a drought condition.
What About Groundwater Levels?
As a drought progresses, aquifers might be drawn down at increasing rates by large users, causing interference with other users on the same aquifer. At present, there are no low water criteria based upon groundwater levels, although the OLWR Plan recognizes the need to develop such criteria to aid in formulating decisions on low water conditions.
The Provincial Groundwater Monitoring Network (PGMN) and its associated Information System were developed by MOE, in partnership with MNR and conservation authorities, to meet the need to “characterize the location, quality and sustainable yield of the resource and to describe where, how and why the resource is changing.” The PGMN presently consists of 465 monitoring wells equipped with data loggers and real-time data transmission to MOE and MNR offices.
Data collected from the PGMN is being evaluated as a possible additional source of information to guide decisions on response to low water. Currently, MOE staff members are developing techniques to set criteria for groundwater condition thresholds that can inform and support decisions made under the OLWR Plan. However, PGMN stations focus on ambient monitoring, which means that most water well monitoring locations have been intentionally located away from major local influences like large municipal water takings. This design feature may work against the usefulness of the data to WRTs, since monitoring locations may be geographically separated from areas of the most significant use during hot and dry periods.MOE is currently working on developing indicator criteria using the available PGMN data. There are also studies underway to assist in better understanding links be- tween stream fows, groundwater and precipitation.
Climate change, water withdrawals and other forces promise to profoundly affect Ontario’s water environment in the coming years, and will significantly affect urban and rural water users’ ability to consume and need to conserve water. The ECO is pleased to note a number of recent positive changes to water management policies and practices in Ontario which will aid in adapting to current and future hydrological changes. These include the following:
- water budgets are being developed for most highly utilized watersheds under the Clean Water Act, 2006;
- monitoring of water quantities taken under PTTWs is now required; and
- studies are underway on groundwater and surface water interactions which will better inform water permitting.
However, the ECO remains concerned that there still are a number of serious gaps in water management practices – when low flow and drought conditions occur, the OLWR Plan may not function adequately. The voluntary implementation of water use reductions under Level One and Level Two requires communication with the public and stakeholders; however, there is generally little ability to monitor the effectiveness of these communications, despite the fact that such an evaluation is required to support a request to the provincial authority for a Level Three condition declaration.
The ECO is greatly concerned that it seems prohibitively difficult to obtain a Level Three condition declaration by the province. The requirements that must be fulfilled by the WRTs, as outlined previously, are too restrictive, in the opinion of the ECO. It is diffcult for the WRTs to provide proof of voluntary implementation by “a majority of the water users.” It could conceivably take nearly a month for a WRT to gather and document this information – time during which streams could dry up. The ECO is aware of two streams, one an important coldwater fish habitat, which completely dried up in summer of 2007, without a Level Three condition being declared under the OLWR Plan. This loss of a prime coldwater stream is certainly a signifcant environmental impact and clearly the mechanisms of the OLWR Plan were not working if its loss could not be prevented. The ECO is aware that MNR and the conservation authorities are addressing the need to streamline the system and the ECO hopes that obstacles will be removed and resources made available to increase the effectiveness of delivery and monitoring of the program at the local level.
Water Allocation and Budgeting
The ECO has commented in the past concerning over-allocation of water under the PTTW system. Water budgets established in the source water protection planning stage under the Clean Water Act, 2006; will be a valuable tool to help inform PTTW decision-making and ensure that water is managed through the program in a long-term sustainable manner. Recently introduced requirements that PTTW holders carry out monitoring of water taking rates are also an important tool. Overallocation in some watersheds nonetheless exists and when low water conditions occur in these watersheds, restrictions are far more challenging to implement. As water budgets become available, the ECO recommends that MOE phase in a PTTW issuance process that builds in stepwise use reduction criteria geared to low fow level conditions. It may also be worth considering the process used in some American states where all water taking permits for a single watershed have identical renewal dates. This allows for regionally coordinated planning for water allocation and budgeting.
The ECO has also commented in past reports on the need for MOE to develop a clear policy for prioritizing water uses to ensure that PTTWs are allocated in both an ecologically sustainable and socially desirable manner (see Water Taking and Transfer Regulation under the OWRA, as well as the Supplement to the 2005-2006 Annual Report pages 114-153). This is particularly important in view of the increased demands placed on our water resources by a growing population, and at a time when our hydrology appears to be changing. The security of our water resources and the ecological, social and economic systems dependent upon them require the Ontario government to begin developing water supply priorities and an overall provincial water allocation strategy.
The ECO recommends that MOE revise its PTTW regulation and its basic terms and conditions for permits to take water to include mandatory water use reduction rules consistent with the Ontario Low Water Response plan.
|This is an article from the 2007/08 Annual Report to the Legislature from the Environmental Commissioner of Ontario.|
Citing This Article:
Environmental Commissioner of Ontario. 2008. "Drought in Ontario? Groundwater and Surface Water Impacts and Response." Getting to K(No)w, ECO Annual Report, 2007-08. Toronto, ON : Environmental Commissioner of Ontario. 49-56.