SOP 4: Community Based Drinking Water and Sanitation
The impact of climate change on community water and sanitation systems can be extreme as the result of existing water and sanitation systems being ill-equipped to cope with changes in the water quantity and quality.
The impact of climate change on the small water and sanitation systems in communities can be considered to be twofold. Firstly, existing water and sanitation systems may be ill-equipped to cope with changes in the water quantity and quality; additional or different treatment may be required to deal with changes in water quality, pumping may need to be added and more storage provided. Secondly, it is possible that there could be an increase in extreme weather events such as hurricanes. Existing hurricane activity already impacts water infrastructure through landslides that compromise storage integrity and damage pipelines, damage to intake works and boreholes through sediment and debris, damage to pump stations either directly due to floods or loss of power, and damage to sanitation facilities which lead to threats to public health.
Water Treatment System
Most small community drinking water systems are bound to a singular water source, therefore diversification of the water source to protect from climate impacts is not possible. Most community systems are served from surface water sources therefore, watershed protection is a critical element in having control of the watershed in order to have adequate supply and protect water quality. For communities that utilize wells as a source of water equipment flooding is a potential impact from an extreme climate. Floodwaters can directly influence the well when debris carried by floods impact the structure, damaging or destroying caps, vents, piping, and the well casing and pump components. Selecting the appropriate site for a well can also reduce water contamination risks from potential contamination sources such as latrines and agricultural fields.
Sanitation
Interruption of sanitation services cause by climatic events often compromises the health and social benefits derived from their installation. To withstand the shocks from climate change, sanitation systems can be made ‘climate-proof’— more robust to climate hazards. Examples include raising toilets above flood levels, increasing structural strength of treatment systems or sewers adjacent to waterways, and locating sanitation infrastructure to minimize potential damage. Another approach is to deploy low-cost sanitation technologies that can be quickly rebuilt, provided they do not create public health or environmental threats if they fail.
Operations and maintenance
In addition to impacts to assets, all communities are also having to revise infrastructure and operations in response to climate impacts. The impact of reduced water supply and forced interruption of customer demand use causes some equipment and systems to become idle for a period of time. Reactivation of idled equipment and systems requires modification of operating procedures and in some instances increase maintenance requirements such rechlorination. In order to manage the decrease in chlorine in the distribution system, flushing of water mains, increased water sampling and/or modified treatment systems operations could be required.
Exercise SOP4: Padlet
Answer the following questions and post your responses in the Padlet available at the bottom of the page.
- What are the climate impacts to smaller water and sanitation systems?
- What operating or technical assistance the water utilities can offer?
SOP 5: Nature-Based Solutions
Nature-based solution for water supply and sanitation is a move away from human-built, or “grey” or “engineered” solutions that use infrastructure to improve water management to one where ‘green’ infrastructure focuses on preserving the functions of ecosystems both natural and built to improve the management of water resources. For water utilities the implementation of NbS can have multiple benefits, for example, managing and restoring vegetation can enable the root systems of trees and other vegetation to stabilize and restrain soils and help to reduce landslides, erosion and flood risk.
Vegetation Management
Vegetation management strategies within water catchment areas should seek to mitigate the transmission of pollutants, such as sediment, agricultural chemicals, or other liquid and solid waste into the water bodies. The most effective measure is the installation of vegetated buffer zones along the entire length of the water channels. Protecting water recharge areas through forestation and watershed management are important in water quality and quantity preservation.
Erosion and Sediment Control
In large storms significant quantities of material can be lost due to erosion of soil which can significantly impact water quality. The problems of erosion are aggravated over steep terrain, particularly where soils are loosely consolidated such as clay and organic matter content, and where land management regimes such as inadequate vegetation and residue cover, and poor drainage leave the soil exposed to rain drop impact and subject to unimpeded runoff.
Mangroves and coastal wetlands
The restoration of wetlands, mangroves, marshes, and oyster reefs, and the installation of living shorelines help reduce wave impacts during storms. Marshes collect sand and sediments from the water and can grow in elevation as sea levels rise, while grey infrastructures cannot adapt and must be updated or replaced to deal with higher water levels.
Exercise SOP 5: Padlet
Answer the following questions and post your responses in the Padlet below.
- What are the technical, governance or financial barrier to implementing NbS?
- How can NbS be mainstreamed in to national or high-level policy, legislation and regulations?