HRM

1. Groundwater Management Concept
• Watershed concepts: water management, land management,
integrated management
• Groundwater supply management
• Artificial recharge enhancement
• Spring protection and development
• Groundwater demand management
• Adaptive management of groundwater

2. Conjuctive Water Managment What is it?
 Surface water and groundwate are in a hydrologic connection
 Conjunctive water use is an approach that recognizes this connection and
tries to utilize it to use the overall water supply more efficiently.
 Conjunctive use involves the combination of surface water
and groundwater sources to meet a single demand.
Conjunctive management of groundwater and surface water
resources

3. Concepts on conjunctive use of surface water and groundwater
 Conjunctive use refers to the coordinated utilization of surface-water and
groundwater resources in an integrated manner appreciating
interdependence as well as different characteristics of the two sources of
water.
 The role of conjunctive use is particularly significant today, more than ever
before, when there is growing need to satisfy the ever increasing water
demand within the limited resources available while considering
various social and environmental impacts of water utilization and protecting
the resources for sustainability.
 Most conjunctive-use schemes throughout the world have developed for
one of the two reasons:
(a) the demand on either surface water or groundwater
resources was too large, or
(b) the quality of extracted groundwater was sufficiently poor
to require mixing of groundwater with surface water.

4. Conjunctive use management of surface waters and
groundwater could provide the following benefits
 Reduce or eliminate areas of overdraft of the groundwater basin.
 Increase storage of groundwater for water during drought years
and surface water shortage.
 Protect the aquifer capacity by controlling compaction of water-
bearing materials and preserving storage capacity in critical areas.
 Control and prevent deteriorating groundwater quality of
groundwater basin.

5. What is Artificial Recharge
 Artificial recharge is the process by which the ground water recharge is
augmented at the rate much higher then those under natural condition of
percolation.
Artificial Recharge Enhancement
• To enhance the groundwater yield in depleted the aquifer due to
urbanization .
• Conservation and storage of excess surface water for future requirements.
• To improve the quality of existing groundwater through dilution
• To improve bacteriological and other impurities from sewage and waste
water by natural filtration , so that water is suitable for re use .
Advantage of artificial recharge

6. Why Artificial Recharge
 In most low rainfall areas of the country the availability
of utilizable surface water is so low that people have to
depend largely on ground water for agriculture and
domestic uses.
 So in order to improve the ground water situation it is
necessary to artificially recharge the depleted ground
water aquifer.

7. Identification of areas for recharge
 Where ground water level are declining due to over
exploitation.
 Where substantial part of aquifer has already been
desaturated i.e. regeneration of water in wells and hand
pumps is slow after some water has been drawn.
 Where availability of water from wells and hand pumps
inadequate during the lean months.
 Where ground water quality is poor and there is no
alternative source of water .

8. Quality of source water
 Problems which arise as a result of recharge to ground
water are mainly related to the quality of raw waters that
are available for recharge and which generally require
some source of treatment before being used to recharge
installations.
 A major requirement of waters that are to be used in
recharge projects is that they be silt free.

9. Methods of Artificial Recharge
 The techniques of artificial recharge can be broadly Categorized as follows:

10. Surface (spreading ) method
 These methods are suitable where large
area of basin is available and aquifers
are unconfined without impervious layer
above it .
 The rate of infiltration depend on the
nature of top soil , if soil is sandy the
infiltration is higher than those of silty
soil .
 The presence of solid suspension in
water used for recharge clogs the soil
pores leading to reduction in infiltration
rate i.e. recharge rate
 Water quality also affects the rate of
infiltration .
Figure : surface spreading basin

11.  Surface Spreading
This method consists of increasing the surface area of infiltration by releasing
water from the source to the surface of a basin, pond, pit or channel.
Most efficient and most cost-effective method for aquifer recharge.
However, only phreatic (unconfined) aquifers can be recharged by the spreading
method, which also
 requires large surface areas to accommodate the recharge scheme,
 allowing water to evaporate if percolation in the ground is slow.
It needs two structures:
 the diversion structure and - the infiltration scheme.
 Other techniques may also be identified with the surface spreading method:
 spate irrigation,
 check dams,
 underground dams and
 sand dams.

12. B.Sub – Surface Method
 In this method the
structure lies below the
surface and recharges
ground water directly.
 The important
structures commonly
use are recharge wells,
recharge shaft, dug
wells etc

13. Recharge well
 Recharge wells can
be of two types-
 (a) Injection well,
where water is “
pumped in” for
recharge and
 (b) Recharge well,
where water flows
under gravity.

14. Rainwater harvesting through recharge well

15. These techniques can serve the following purposes:
 Provide drinking water
 Provide irrigation water
 Increase groundwater recharge
 Reduce storm water discharges, urban floods and
overloading of sewage treatment plants
 Reduce seawater ingress in coastal areas.
Rainwater harvesting through recharge well

16. Injection Well  The injection wells are
similar to a tube well.
 This technique is suitable
for augmenting the ground
water storage of deeper
aquifers by “pumping in”
treated surface water.
 These wells can be used as
pumping wells during
summers.
 The method is suitable to
recharge single aquifer or
multiple aquifers.
 The recharge through this
technique is comparatively
costlier and required
specialized technique.

17. Recharge Well  The recharge well for shallow water
table aquifers up to 50 m are cost
effective because recharge can take
place under gravity flow only.
 These wells could be of two types, one
is dry and another is wet.
 The dry types of wells have bottom of
screen above the water table. In such
well excessive clogging is reported due
to release of dissolved gasses as water
leaves the well and on other hand
redevelopment methods have not
been found effective in dry type of
well.
 The wet types of wells are in which
screen is kept below water table.
These wet type wells have been found
more successful.

18. Dug Wells
 In alluvial as well as hard rock
areas there are thousand of
dug wells have either gone
dry due to considerable
decline of water levels.
 These dug wells can be used
as recharge structure storm
water and other surplus water
from canal etc. can be
diverted into these structure
to directly recharge the
dried aquifer.
 The water for recharge
should be guided through a
pipes to the bottom of well to
avoid entrapment of bubbles
in the aquifer.
By channelling run-off to disused
dugwells, recharge wells are
created
Recharge well

19. Induced Recharge
 It is an indirect method of
artificial recharge involving
pumping from aquifer
hydraulically connected with
surface water such as perennial
streams, unlined canal or lakes.
 The heavy pumping lowers the
groundwater level and cone of
depression is created .
Lowering of water levels
induces the surface water to
replenish this ground water .
 This method is effective where
stream bed is connected to
aquifer by sandy formation .

20. Springs Development
 The natural outflow of groundwater at the earth’s surface
 They occur because the hydraulic head in the aquifer system
intersects the land surface.
20

21. Springs protection and development
• Springs occur wherever groundwater flows out from the earth’s surface.
• Springs typically occur along hillsides, low-lying areas, or at the base of
slopes.
• Springs are sometimes used as water supplies
Spring Development
• A spring can be developed into a drinking water supply by collecting the
discharged water using pipe and running the water into some type of sanitary
storage tank
• Protecting the spring from surface contamination is essential during all phases
of spring development

22. A protective box that enables:
• collection of water
• discharge to a tap for collection at
the spring
• discharge downhill by distribution
pipe
Spring box with discharge pipe leading down hill,
Nias, Indonesia
Spring Development

23. From Oxfam technical brief
Spring being protected, Zaire - S House / WEDC
• May be harvested in a number of
ways
• Should always be protected from
degradation.
Spring Development

24. Figure Fracture spring near
Mereme-eti, south of Mekelle.
Spring Development
Figure Developed contact spring (at
the base of the Adigrat Sandstone) in
Agbe, southeast of Abi Adi

25. Plate 14. Cold spring recharge by basalt-Garamuleta
Spring Development

26. Spring Development Considerations
• When considering using a spring as your source of drinking water, it is
important to ensure that the rate of flow is reliable during all seasons of
the year.
• Water quality is also important to consider before using a spring as a
water supply
• Before developing the spring, collect a sample of water and have it
analyzed at a local water testing laboratory to ensure that it can be
efficiently and economically treated to make it safe for human consumption
• Springs are highly susceptible to contamination since they are fed by
shallow groundwater, which usually flows through the ground for only a
short period of time and may interact with surface water. For this reason,
most springs will need some treatment before the water is considered a
safe source of drinking water. Testing will help determine exactly how
much treatment will be necessary and may help determine if other sources
of water would be more economical.

27. • The key to successful spring development is to ensure there is
adequate water flow and water quality for the intended purpose.
• Several design considerations are involved when developing
a spring, and their importance will largely depend on the
intended water use
Design considerations are:
• Bacteriological contamination from the ground surface and/or
livestock accessing the area around the spring
• The elevation of the spring with respect to the surrounding
area and also the location to where the water is to be supplied
• The flow rate of the spring and the amount of water
required
• Protect the resource by not taking more water from the
spring than you need.

28. Managing groundwater demand
• Conservation and water efficiency
• Good land use planning and well construction policies
• Limiting groundwater use
• Reduce unaccounted for water…water supply pipe network is
very old and served beyond its service time
• Looking at tariff structures
Tariff structures particularly for large consumers should reflect
and should encourage efficient water use
Groundwater demand management

29. GROUNDWATER AND CLIMATE CHANGE
Groundwater as part of hydrologic cycle
• The hydrologic cycle primarily governed by the balance between input
(Precipitation/rain) and output (Evapotranspiration, runoff and discharge)
• The components of the groundwater balance are displayed in the figure and consist
of recharge (direct recharge and inter-aquifer flows) and discharge (groundwater
flow to streams, springs, lakes, wetlands, oceans; groundwater abstraction;
evapotranspiration).
• The difference between recharge and discharge determines the change in the
volume of groundwater.
• Variations in climate will induce hydrologic change

30. Relationship Between Groundwater and Climate Change
• Groundwater is the major source of water across much of the world,
particularly in rural areas in arid and semi-arid regions, but there has
been very little research on the potential effects of climate change.”(IPCC
2001, p. 199)
• Despite the critical importance of ground-water resources in many parts of the
world, there have been very few direct studies of the effect(s) of global
warming on groundwater recharge.”(IPCC 1996, p. 336)
• Currently, more than 80% of Ethiopia’s drinking water
supply comes from groundwater (Awulachew et al., 2007).
• Increasing demand due to an increase in population and
climate change will further increase dependence on
groundwater.

31. How will groundwater be affected by Climate Change
• Groundwater will be less directly and more slowly impacted by climate
change, as compared to e.g. rivers.
• This is because rivers get replenished on a shorter time scale.
• Only after prolonged droughts groundwater levels will show declining
trends.
• Groundwater systems both discharge into and are recharged from
surface water, impacts on surface water flow regimes are expected to
affect groundwater.
• Any variation in climate has the potential to affect input into the
groundwater (recharge) and output into surface water bodies as base
flow and springs (discharge), either directly or indirectly as vapor
return into atmosphere.

32. CLIMATE AND NON-CLIMATE FACTORS
RECHARGE
• Precipitation: main driver: not only the magnitude
but also intensity, frequency, seasonality
• Temperature and CO2 may affect evapotranspiration
> portion of rainfall that infiltrates
• Changes in river flow will affect infiltration (and discharge)
• Land cover and land use <> climate change
• Non climate factors: land use changes, population growth, poor
management

33. Impact of Climate Change in Groundwater Storage
• Deeper aquifers react, with delay, to large-scale climate
change but not to short-term climate variability.
• Shallow groundwater systems (especially unconsolidated
sediment or fractured bedrock aquifers) are more responsive
to small scale climate variability (Kundzewiczand Döll,
2008).
• The impacts of climate change on storage will also depend
on whether or not groundwater is renewable (contemporary
recharge)

34. Impact of Climate Change in Groundwater Quality
• In shallow aquifers, groundwater temperatures may increase due
to increasing air temperatures.
• In arid and semi-arid areas increased evapotranspiration may
lead to groundwater salinization(van Vliet, 2007).
• In coastal aquifers, sea level rise and storm surges are likely to
lead to sea water intrusion and salinization of groundwater
resources.
• Changes in recharge and discharge are likely to change the
vulnerability of aquifers to diffuse pollution (van Vliet,
2007).

35. What is adaptation?
• Adaptations are adjustments made in natural or human systems
in response to experienced or projected climatic conditions or
their beneficial or adverse effects or impacts (Smit et al., 2001)
• Adaptations are essentially management responses to risks
associated with climate variability and climate change.
• Adaptive Management can also be termed as ‘learning from
managing’.
• The philosophy of Adaptive Management is to continually
improve policies and practices by learning from the outcomes
of previous work
CLIMATE CHANGE ADAPTATION

36. CLIMATE CHANGE ADAPTATION
• Managing grw. recharge
• Management of grw. storage
• Protection of grw. quality
• Managing demands for grw.
• Managing grw. discharge
Managing groundwater recharge
Protecting
groundwater
quality
Managing
demand for
groundwater
Managing groundwater
discharge
Managing
groundwater
storage
Adaptation: management responses for grw. dependent systems to risks
associated with climate variability and climate change