Project funded
by theEU–DGEnvironment
L
andsurfacerelevant
forapplication
Artificial surface
Agriculture land
Forest and semi-natural areas
Wetlands
F
inancialcosts
(C
apital
,
operation
&
maintenance
)
Typically, the responsible authority owns much of the catchment thus
land acqui-
sition
costs may be relatively minor. If not, acquisition costs may be considerable
and other mechanisms such as easements or landowner
agreements
should be
considered. The capital costs of afforestation can be lower than the cost of other
approaches to controlling water quality in drinking water.
D
esign
Generally
as much of the reservoir
catchment as possible should be affo-
rested such that protection can be maximized without undue reduction in reservoir
inputs due to higher evapotranspiration from forest cover. The
riparian
areas
should be prioritized. Afforestation of more steeply sloping areas is likely to result
in greater benefits related to sediment retention.
S
cale
Reservoirs are typically located in
me-
soscale
catchments so as to have suffi-
cient contributing area for precipitation
capture. However, the benefits are largely
scale independent.
Afforestation
of previously bare or heavily eroded areas in reservoir catchments 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. However less
precipitation may be available for reservoir recharge due to the potentially greater interception and evapotranspiration associated with forests.
Afforestation of artificial or agricultural sur-
faces is a form of land use conversion (F5).
FORESTRY
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