BUREAU OF GEOLOGY


an appropriate mining method. The groundwater levels in peatlands may
also influence groundwater levels in aquifers which are connected hydro-
logically (King, et al., 1980). It is important to define the relationship, or
lack of relationship, between peatlands which are to be mined and aqui-
fers which might possibly be affected by removal of peat.
 If coastal peatlands are to be mined, the drainage necessary to reduce
water levels could possibly lead to saltwater intrusion. In addition,
groundwater recharge may be reduced and groundwater levels could be
lowered (King, et al., 1980). The combination of these three effects
could lead to saltwater intrusion and King, et al. (1980) suggest the
effects of this change should be researched carefully before develop-
ment.
 Peat mining will require construction of drainage ditches, water control
devices and roads. Thus, the patterns of surface water flow in the mined
area and in downstream channels will be modified (King, et al., 1980).
 It is believed (King, et al., 1980) that peatland development will
increase minimum stream discharge. Net evapotranspiration from the
peatland will be reduced since vegetation must be cleared in order for
mining to occur. Thus, a greater portion of net precipitation will drain. As
ditches are constructed, more of the peatlands will be able to contribute
flow directly to artificial surface streams (King, et al., 1980).
 A number of factors associated with peat mining will serve to increase
mean surface water discharge. If the mining method chosen involves
drainage, then water being drained will be added to surface water dis-
charge. Additionally, mined peat will have to be dewatered, so another
addition to surface water discharge occurs. It is projected (King, et al.,
1980) that the effects of a small scale development on mean surface
discharge would be minor. Proposed moderate and large scale mining
operations should be evaluated on a site specific basis to protect down-
stream water users and aquatic resources (King, et al., 1980).
 The development and reclamation of a peatland will permanently
change the hydrologic budget of the area (King, et al., 1980). These
changes may be helpful or detrimental offsite.
 If peatlands contribute to aquifers in a given area, then the effect of
positive or negative changes affecting that aquifer should be researched.
The groundwater flow from peatlands to connected regional aquifers will
change with mining (King, et al., 1980).
 Lastly, the evapotranspiration rate from the mined area will change
(King, et al., 1980). Since mining involves removal of surface vegetation,
net evapotranspiration will be reduced. Ditching will lower the ground-
water level and cause a moisture deficiency in the upper portion of the
drained area which will contribute to a lower net evapotranspiration rate.
Although the effects of these changes are expected to be minor for all
scales of development, the modifications in adjacent plant and animal
communities and in local climate are poorly understood (King, et al.,
1980).