Integrated Water Resources Management (IWRM) for the Preservation
199
2.3 Northern Stafford County
In much of northern Stafford County (Figs. 1 and 2) the Great Bend Prairie aquifer
is divided into deep and shallow zones separated by a thin, semi-permeable layer
of clay. The deep aquifer is quite saline in many areas, due to salt-water intrusion
from the Permian bedrock. As the deep aquifer is in contact with the Permian
bedrock, only the low permeability of the bedrock precludes complete penetration
of the bedrock brine into the deep aquifer. It is suspected that pumping from the
shallow aquifer has accelerated the mineralization of the deep aquifer by changing
the vertical head gradient.
Since the deep aquifer is almost completely saline, it presently supplies salinity
into the shallow aquifer. Fresh groundwater resources of the shallow aquifer are
presently threatened not only by salinity penetration from the deep aquifer, but
also by increasing nitrate concentration, resulting from agricultural practices
(especially fertilizer application). Continuation of this degradation of fresh
groundwater resources will pose a serious threat to the agricultural activity and
rural communities in the region.
As is the case with water supply needs of the wildlife refuge (see above), there
are no available sources of water to replace groundwater lost to contamination or
to make up for precautionary reductions in pumping. Irrigation with local treated
wastewater of the urban community of Great Bend (about 17 000 people; Fig. 1)
might be considered. However, this source is much too small to supply
agricultural demands in the dry season.
3 Application of the IWRM Approach
3.1 Creation of Adequate Data Bases
Adequate collection and assembly of relevant data are crucial for the proper use of
the IWRM approach. Water-resource management problems are often only
qualitatively defined; data collection can provide quantitative perspectives and
problem definition. However, monitoring and data collection should be
accompanied by theoretical analyses and development and testing of hypotheses.
This will provide guidelines for the types, locations, and appropriate techniques of
data collection.
For many years it was well known that the Great Bend Prairie aquifer is
subject to salt-water intrusion, as illustrated in Figs. 1 and 2. However, even in
these figures there are some question marks with regard to the appropriate location
and boundaries of the different formations and concentration regimes.
Furthermore, quantitative values of parameters affecting the mineralization
process, as well as information on the availability of different types of local and
regional water resources were required for the adoption of the IWRM approach.
199
2.3 Northern Stafford County
In much of northern Stafford County (Figs. 1 and 2) the Great Bend Prairie aquifer
is divided into deep and shallow zones separated by a thin, semi-permeable layer
of clay. The deep aquifer is quite saline in many areas, due to salt-water intrusion
from the Permian bedrock. As the deep aquifer is in contact with the Permian
bedrock, only the low permeability of the bedrock precludes complete penetration
of the bedrock brine into the deep aquifer. It is suspected that pumping from the
shallow aquifer has accelerated the mineralization of the deep aquifer by changing
the vertical head gradient.
Since the deep aquifer is almost completely saline, it presently supplies salinity
into the shallow aquifer. Fresh groundwater resources of the shallow aquifer are
presently threatened not only by salinity penetration from the deep aquifer, but
also by increasing nitrate concentration, resulting from agricultural practices
(especially fertilizer application). Continuation of this degradation of fresh
groundwater resources will pose a serious threat to the agricultural activity and
rural communities in the region.
As is the case with water supply needs of the wildlife refuge (see above), there
are no available sources of water to replace groundwater lost to contamination or
to make up for precautionary reductions in pumping. Irrigation with local treated
wastewater of the urban community of Great Bend (about 17 000 people; Fig. 1)
might be considered. However, this source is much too small to supply
agricultural demands in the dry season.
3 Application of the IWRM Approach
3.1 Creation of Adequate Data Bases
Adequate collection and assembly of relevant data are crucial for the proper use of
the IWRM approach. Water-resource management problems are often only
qualitatively defined; data collection can provide quantitative perspectives and
problem definition. However, monitoring and data collection should be
accompanied by theoretical analyses and development and testing of hypotheses.
This will provide guidelines for the types, locations, and appropriate techniques of
data collection.
For many years it was well known that the Great Bend Prairie aquifer is
subject to salt-water intrusion, as illustrated in Figs. 1 and 2. However, even in
these figures there are some question marks with regard to the appropriate location
and boundaries of the different formations and concentration regimes.
Furthermore, quantitative values of parameters affecting the mineralization
process, as well as information on the availability of different types of local and
regional water resources were required for the adoption of the IWRM approach.