1 Introduction
2 Materials and Methods
2.1 Study Area
Policy | Year of introduction | Description |
---|---|---|
Restrictions on new connections to the public grid | 2000 | A full stop on new connections to the public water grid is enacted. No new requests are accepted until local water self-sufficiency can be ensured. Exceptions are made to communities of households where inadequate drinking water supply or quality poses a threat to human health. |
Water use restrictions | 2007 | Consumers connected to the public grid are prohibited to use water from the municipal grid for gardening and swimming pools. In 2007 the restrictions applied from June to September, but the duration was gradually extended, and since 2016, restrictions apply from April to October. |
Information campaigns | 2007 | Information on the state of groundwater resources starts being communicated by the municipality on their website. |
Minimum well-capacity requirements | 2008 | Documentation of a minimum well-capacity of 600 l per hour becomes a requirement for building permits to be issued to new off-grid house construction projects. |
New aquifer exploitation | 2016 | A new municipal aquifer is identified and taken into use in 2016 to supplement the existing aquifer. Exploitation of the aquifer is terminated in 2018 due to unsatisfactory water quality. |
Information campaigns | 2017 | An information campaign to encourage water savings in households and among tourists is launched. Information and encouragement to use water more efficiently is communicated in media, on tourist resorts and on the ferry to the island. |
2.2 Methods
2.2.1 Model Development
2.2.2 Model Analysis
3 Results
3.1 Historic Behavior and Model Structure
3.2 Results from Feedback Loop Analysis
Feedback loop | Description |
---|---|
B1 | Causal chain: on-grid water gap ➔ on-grid water supply ➔ water transports ➔ on-grid water gap |
Behavior: as the on-grid water gap expands this trigger more water transports which closes the gap by increasing the on-grid water supply. | |
B2 | Causal chain: total on-grid water use ➔ actual capacity gap ➔ restrictions on new connections to public grid ➔ connections to public grid ➔ on-grid households ➔ household water use ➔ total on-grid water use |
Behavior: when total on-grid water use grows, this expands the actual capacity gap, which makes the municipality enforce stronger restrictions on new connections to public grid. The restrictions reduce the number of connections to the public grid, thereby maintaining the number of on-grid households and household water use lower than and they would otherwise have been which reduces total on-grid water use. | |
B3 | Causal chain: actual capacity gap ➔ water use restrictions ➔ water use per capita ➔ household water use ➔ total on-grid water use ➔ actual capacity gap |
Behavior: if household water use increases, total on-grid water use will also increase, and the actual capacity gap expands. The expanded gap causes the municipality to enforce stronger water use restrictions which drives down water use per capita and makes household water use decline again. | |
B4 | Causal chain: on-grid water gap ➔ water use per capita ➔ household water use ➔ total on-grid water use ➔ on-grid water gap |
Behavior: if the on-grid water gap grows very large this will eventually cause water use per capita to decrease due to supply failures. The reduction in water use per capita will cause household water use and total on-grid water use to decrease, eventually reducing the on-grid water gap. | |
B5 | Causal chain: on-grid water gap ➔ perceived water sufficiency ➔ destination attractiveness ➔ tourists ➔ total on-grid water use ➔ on-grid water gap |
Behavior: if the on-grid water gap increases to a level where it starts influencing water supply to tourist facilities this will cause the perceived water sufficiency to decline, reducing the destination attractiveness of Fårö. Falling destination attractiveness will cause the number of tourists to decline and total on-grid water use to go down, making the on-grid water gap shrink due to lower demand. | |
B6 | Causal chain: on-grid water gap ➔ perceived water sufficiency ➔ destination attractiveness ➔ property prices ➔ housing standards ➔ water use per capita ➔ household water use ➔ total on-grid water use ➔ on-grid water gap |
Behavior: if the on-grid water gap is closed, the perceived water sufficiency goes up and destination attractiveness increases. Higher destination attractiveness leads to higher property prices which over time drives up housing standards. Higher housing standards increases average water use per capita, increasing household water use and total water use, causing the on-grid water gap to expand again. | |
B7 | Causal chain: on-grid water gap ➔ perceived water sufficiency ➔ water use per capita ➔ household water use ➔ total on-grid water use ➔ on-grid water gap |
Behavior: if the perceived water sufficiency increase, this causes an increase in water use per capita, higher household water use and a growing total on-grid water use. The increased water use causes the on-grid water gap to expand and perceived water sufficiency among consumers declines again. | |
B8 | Causal chain: off-grid households ➔ private wells ➔ fraction of aquifer exploited ➔ new constructions ➔ off-grid households |
Behavior: When the number of off-grid households increase, this leads to more private wells being drilled and the fraction of aquifer exploited increases. This pushes down the number of new constructions because it gets progressively harder to find new housing sites with sufficient aquifer capacity for exploitation, thereby reducing further growth in off-grid households. | |
B9 | Causal chain: on-grid households ➔ connections to public grid ➔ on-grid households |
Behavior: If the number of on-grid households increase fewer new connections to public grid will be allowed by the municipality, keeping the number of on-grid households below what they would otherwise have been. | |
B10 | Causal chain: off-grid households ➔ connections to public grid ➔ off-grid households |
Behavior: The municipality generally do not approve new households to connect to the public grid because of the current low level of water self-sufficiency. However exceptions are sometimes made and thus, if the number of off-grid households increase the number of new connections to the public grid will also increase, thereby reduce the number of off-grid households below what it would otherwise have been. | |
B11 | Causal chain: off-grid water use ➔ off-grid water gap ➔ off-grid water use |
Behavior: If the off-grid water use increases this will increase the off-grid water gap, and if the gap grows big enough it will reduce the off-grid water use below what it would otherwise have been. | |
B12 | Causal chain: water extraction at tap station ➔ off-grid water gap ➔ water extraction at tap station |
Behavior: If the off-grid water gap increases, e.g. because demand exceeds the supply capacity of the private wells, this will lead to more households having to go to the municipal tap station to get their water. Water extraction at the public tap station will increase and the off-grid water gap to be momentarily reduced. | |
B13 | Causal chain: destination attractiveness ➔ new constructions ➔ off-grid households ➔ off-grid water gap (either via off-grid water use or via private wells) ➔ water extraction at tap station ➔ total on-grid water use ➔ on-grid water gap ➔ perceived water sufficiency ➔ destination attractiveness |
Behavior: If the destination attractiveness of Fårö increases this leads to more new constructions and therefore a growth in the number of off-grid households. More households lead to a greater off-grid water use and a growing off-grid water gap. The off-grid gap is closed by increasing water extraction at tap station, which increases the total on-grid water use. This leads to a greater on-grid water gap (effectively moving the gap from off-grid to on-grid). The growing on-grid water gap contributes to a lower perceived water sufficiency, dampening further growth in destination attractiveness. | |
R1 | Causal chain: actual capacity gap ➔ restrictions on new connections to public grid ➔ connections to public grid ➔ off-grid households ➔ off-grid water use ➔ off-grid water gap ➔ water extraction at tap station ➔ total on-grid water use ➔ actual capacity gap |
Behavior: When the actual capacity gap grows the municipality imposes more restrictions on new connections to the public grid. More restrictions cause fewer connections to the public grid, in effect reducing the movement of households from off-grid to on-grid, keeping the number of off-grid households above what they would otherwise have been. More off-grid households increase the pressure on the off-grid water system, resulting in more off-grid households that will need to use the public tap station. This increases the total public water demand and making the actual capacity gap grow even further. | |
R2 | Causal chain: actual capacity gap ➔ restrictions on new connections to public grid ➔ connections to public grid ➔ off-grid households ➔ private wells ➔ fraction of aquifer exploited ➔ average well capacity ➔ off-grid water gap ➔ water extraction at tap station ➔ total on-grid water use ➔ actual capacity gap |
Behavior: Following the same logic as R1, an increase in actual capacity gap leads to a build up of off-grid households beyond what otherwise would have been. More households lead to more private wells and a greater fraction of aquifer exploited. Over time this leads to a decline in average well capacity because there are fewer and fewer high-capacity well sites left to exploit. This increases the off-grid water gap and, by the same logic as in R1, increases extraction at tap station, rises the total on-grid water use and expands the actual capacity gap even more. |