Surrey’s water system is a complex and highly integrated network of resources, processes, and goals. The water chain and suitability assessments reveal the links between these components and provide information about how the resources function as an overall system.
In Surrey, the most heavily impacted and extracted water resources are the river systems. They receive the output from the agricultural, urban, and industrial land uses that surround them and, as a consequence, experience changes to their quality and quantity along their lengths. Infiltration and surface runoff of stormwater, farm drainage, and residential & industrial effluent have the most problematic impacts, as they introduce serious downstream effects that limit the ability of the rivers to meet their agricultural, recreational, and environmental functions. As development continues in the rapidly growing city, these effects can be expected to increase, and increased management will be required to protect the functionality of the rivers. At this time, the volume of their flows is fully allocated to water licenses, and therefore they offer little promise as a new source of agricultural water.
The rivers are also the most heavily managed and legally protected water resource in Surrey; however the management is disjointed and lacks common objectives. They are monitored regularly for a variety of quality and quantity objectives; however the monitoring programs are managed by different governing bodies and are not coordinated with each other. As a result, these monitoring programs provide valuable data about the rivers but provide little information about the systemic causes of water problems and fail to integrate system-wide objectives. To operate management systems in such a disjointed fashion is to deny the intrinsic interconnected nature of water resources, and results in inefficiencies in the overall functioning of the water system. Both demand for water and development are expected to increase in Surrey in the years to come – if the water resources are not managed in a more integrated way, the rivers may be unable to achieve all the functions they are used for today.
Groundwater is not widely used for any purpose in Surrey at this time; nonetheless it has an important role in city’s water system and has the potential to provide certain areas with high quality sources of agricultural water in the future. Groundwater is present in large quantities throughout the entire city of Surrey and provides an important source of base flow water for the 3 rivers. The Nicomekl-Serpentine Aquifer, which underlies a large portion of the ALR, may have a high potential to support agricultural production along its borders, where water quality is thought to be of excellent condition. The possibility of using Surrey’s other aquifers is primarily limited by their geographic location and size; although the Newton Upland, Clayton Upland, Hazelmere, Hazelmere Valley, and Grandview aquifers all underlay small portions of the ALR and may provide agricultural opportunities in certain small, localized areas. Groundwater is not regularly monitored at this time, therefore some water quality and quantity testing would be required before any of the aquifers were developed for agricultural production. With the Water Sustainability Act coming into effect in 2016, groundwater will be licensed and managed by the provincial government in conjunction with surface water resources, and monitoring and data collection of aquifers will certainly increase. However, if groundwater resources are to become a new source of agricultural water, the City of Surrey must strive to enact a management and monitoring plan that would mitigate causing serious downstream effects on the rivers that depend upon it for flow volume.
Similar to groundwater, rainwater is not widely used for any function in Surrey; however it is significant input of water into the system, and has a high potential to be harnessed for agricultural production. It is possible to use rainwater inputs for agricultural production in lieu of irrigation; however due to the seasonal patterns of rainfall, this practice can leave crops vulnerable during periods of unexpected drought. In order to overcome the temporal variability of the availability this resource, and thus to harness rainwater with less risk, rainfall must be collected and stored. Although rainwater is not regulated under any legal framework at this time, significant harvesting of rainwater would affect downstream resources, such as rivers, detention ponds, and therefore it may become prudent for the city to regulate and manage this resource as well. Furthermore, the harvesting of rainwater could help reduce the amount of stormwater runoff that is generated, thereby allowing the city to achieve increased agricultural production and improved flood management in an integrated manner.
Stormwater, drainage detention ponds, and agricultural drainage are considered to be waste products within the Surrey water system, and the main focus of their management is to detain them for flood control and diversion. These resources accumulate via the processes of surface runoff and farm drainage. The main limitation against their immediate use for agricultural production is the current lack of understanding of the quality and quantity of these resources. As waste products, they are likely to contain contaminants that would limit their suitability for agriculture; however they may have the potential to become valuable resources once treated. As such, these resources may represent sites of opportunity for water treatment, harvesting, and agricultural production.
The water chain assessment is also useful for identifying vulnerabilities, inefficiencies, and opportunities within a water system. Two of Surrey’s water system functions (agriculture, aquatic habitat for threatened fish) rely solely on the river system resources. This represents a vulnerability within the functioning of the system. Concurrently, resources such as rainwater and groundwater are not currently used or managed for the achievement of any functions – this represents both an inefficiency and an opportunity. In order for the water system to become more resilient, adaptive, and robust, Surrey should strive to create greater integration among its resources and variety in its use of water resources.