Afforestation of reservoir catchments

Code: 
F03
Sector: 
Forest
The complete description of the NWRM: 
Summary: 

Planting trees in reservoir catchments can have both negative and positive effects. . Afforestation of previously bare or heavily eroded areas can control soil erosion, thereby extending the life of the reservoir and improving water quality. Water quality can also be improved if precipitation is able to infiltrate into forest soils before flowing to the reservoir. These potential improvements in water quality need to be balanced against the possibility that less precipitation will be available for reservoir recharge due to the potentially greater interception and evapotranspiration associated with forests. Studies have indicated decrease of water yield after afforestation of the catchment and with the increase of forest age. Forests in reservoir catchments should typically not be managed for timber production, but maintained in as close to a natural state as possible as the fertilization and ground disturbance associated with intensive forest management can have negative impacts on reservoir water quality. Increased acidification and eutrophication after afforestation with conifer species have also been reported. Use of long-lived native deciduous tree species for afforestation instead of fast growing conifers or eucalypts is likely to bring enhanced biodiversity benefits while minimizing water loss.

Illustration(s): 
Possible benefits with level: 
Benefits Levelsort descending
BP1 - Store runoff High
BP2 - Slow runoff High
BP5 - Increase evapotranspiration High
BP6 - Increase infiltration and/or groundwater recharge High
BP7 - Increase soil water retention High
BP8 - Reduce pollutant sources High
BP9 - Intercept pollution pathways High
BP10 - Reduce erosion and/or sediment delivery High
BP14 - Create terrestrial habitats High
BP17 - Absorb and/or retain CO2 High
ES3 - Natural biomass production High
ES4 - Biodiversity preservation High
ES5 - Climate change adaptation and mitigation High
ES6 - Groundwater/aquifer recharge High
ES8 - Erosion/sediment control High
ES9 - Filtration of pollutants High
ES10 - Recreational opportunities High
ES11 - Aesthetic/cultural value High
PO9 - Take adequate and co-ordinated measures to reduce flood risks High
PO11 - Better protection for ecosystems and more use of Green Infrastructure High
PO14 - Prevention of biodiversity loss High
BP15 - Enhance precipitation Low
PO1 - Improving status of biology quality elements Low
PO2 - Improving status of physico-chemical quality elements Low
PO4 - Improving chemical status and priority substances Low
PO7 - Prevent surface water status deterioration Low
BP12 - Create aquatic habitat Low
ES2 - Fish stocks and recruiting Low
PO13 - Better management of fish stocks Low
BP11 - Improve soils Medium
BP13 - Create riparian habitat Medium
BP16 - Reduce peak temperature Medium
ES1 - Water storage Medium
ES7 - Flood risk reduction Medium
PO3 - Improving status of hydromorphology quality elements Medium
PO5 - Improving quantitative status Medium
PO6 - Improving chemical status Medium
PO8 - Prevent groundwater status deterioration Medium
PO10 - Protection of important habitats Medium
Case study(ies): 
Last updated: 09 Jun 2015 | Top