Specifically for Flanders, expected climate impacts include more floods (both of rivers and sewers) caused by peak rainfall intensities and more droughts caused by longer dry periods. These patterns can already be observed today.
In addition, the vulnerability to these effects of climate change are further intensified by the increase in urbanization associated with a high percentage of build-up areas and paved soil, which is especially the case in Flanders. Soil sealing reduces water infiltration and groundwater recharge (thus reducing water availability) and increases the risk of flooding downstream by accelerated run-off. Sealed soils also reduce the cooling effects from the evaporation of water from soil and vegetation (evapotranspiration) thereby strengthening the urban heat island effect. Together, it is clear that an effective climate strategy also requires a sustainable water management plan, outlining the adaptive measures that need help securing the availability of valuable water resources in the future. The sustainability of these measures depends on restoring and optimally using the services provided by water ecosystems.
Next to the measures discussed earlier to mitigate greenhouse gas emissions, this chapter proposes the contours of a sustainable water strategy for UAntwerp and lists the concrete measures that are possible in the different spatial contexts of the university. UAntwerp is already taking actions for sustainable water management, particularly in new buildings. At the same time, significant scope remains for extending these strategies to already existing infrastructures.
Goals
Three principles guide our sustainable water strategy:
- Reduce,
- Reuse,
- Replenish.
A fourth goal relates to the leverage effects of sharing a strong vision.
- Identify the levers for further reducing the consumption of drinking for other purposes than drinking.
- Harvest and reuse rainwater (and perhaps also grey water) up to cover the maximal extent of water use that does not require drinking water quality.
- Maximize the infiltration of rainwater via the integration of infiltration systems adapted to the specific contexts at hand at the different campuses, reinforcing as much as possible the blue-green infrastructures that combine the adaptive objectives for water and nature management.
- All staff and students are stimulated to develop a shared vision and work towards a sustainable water balance for UAntwerp.
Priority action points
- Funding an integrated assessment (either making use of ample in-house expertise or via an external consultant) to identify and implement the quick-wins at short term as well as a mid-term plan for infrastructure replacement, including:
- Adjusting infrastructure for lower water use (e.g. toilets, taps).
- Seek sustainable alternatives for the most important large water users at the university.
- Assessing whether rainwater can be collected and reused (e.g. for toilet flushing).
- Evaluation of the potential to reuse other water sources such grey water.
- Including a calculation of returns on investment of the above measures
- Switching to smart metering of water use at the level of each functional unit (building, department, ..) and an electronic information system for regular follow-up.
- Designing a communication strategy for awareness based on the more detailed, smart meter data for water use.
- Map the current and potential locations suited for water infiltration:
- Overflows of rainwater tanks and pipes for roof run-off can be disconnected from the sewage system and allowed to infiltrate.
- Above ground infiltration via Wadi’s (‘Water Afvoer Drainage Infiltratie’). Wadi infiltration systems and synergistic blue-green infrastructures that combine multiple functions including recreation, biodiversity and ecological connections, buffer against heat stress, surface water treatment and groundwater infiltration and storage.
- Underground infiltration system are a second option for instance when space is limited.
- Identifying the locations where more rainwater infiltration can be realized by making large sealed surfaces (e.g. for car parking) water permeable.
- Integrate the in-house knowledge at UAntwerp on innovative water technology and nature-based solutions on the campus or the local neighborhood as living labs.
Challenges
- Currently, it is difficult to monitor trends in drinking water usage because metering is only possible at coarse scale (level of the building or even the campus) which makes it hard to identify large users and its cause. To allow a study of potential actions to save drinking water, more detailed data on water consumption is necessary.
- The presence of existing infrastructure easily entails patterns of lock-in. To be able to assess the use of more integral adjustment to a building’s rainwater drainage systems, it is important to include a calculation of the returns on investment of the possible measures.