Wednesday, October 17, 2018

Water Resources of Baluchistan





















Water Resources of Baluchistan

Introduction

The Baluchistan Province comprising of 32 Districts, spreads virtually as a plateau, and area wise is largest Province of the Country. It has boarders with Afghanistan in the North and Iran in the south-west. The characteristic of the Province are :Area-347,185 Sq. Km constituting about 44% of the Country ;  Population 6.566 million as of 1998 census as per population growth rate the present day population is about 10.00 million ; Arid with scanty rainfall varying from 12 to 14 inches in the North to 4to 6 inches per annum in the South.



- Water Resources 
Baluchistan comprises of 44% area of the country. This is the only Province of the country which has some area outside the Indus catchment .The north western portion of about 25.822 m acres drains into the Indus. The remaining area has a separate drainage area. . Kharan Desert, 29.696 m acres  drains into the desert , it isan area of low lands comprising two lakes, Hamun e Maskhel and Humin e Lora, 73.5 % area is mountainous . The rest called Makran area drains into the Arabian Sea; it is 30.272 m acres, with70% mountainous area.
Water resources of the Province are summarized as follow:



, 29.696 m acres , comprising 73.5 % mountaimus


Description
Quantity (MAF)
Available
Utilized
Balance

A.          Indus Water as per Indus Accord

1

Perennial

3.870

3.052

0.820

2

Flood

4.620

--

4.620

Total

8.490

3.052

5.440

B.          Non Indus Basin

1

Flood Runoff

10.793

2.222

8.571
2
Groundwater
2.210
2.659
(-)               0.459

Total

13.003

4.881

8.112

G. Total

21.493

7.933

13.552
  

 Canal System
In Baluchistan canal supplies are small in total and restricted to the east of the Province, adjacent to Sindh Province. For the period 1988-2000 the average canal flow was 1.94 MAF and recharge from these canals was assessed as 0.29 MAF (15% of 1.94 MAF). Most of irrigated area of this Province lies in a saline groundwater zone. Other components of groundwater recharge include return flows from irrigation application, other return flows, sub-surface inflows and recharge from rivers. The recharge from return flows of irrigation application was estimated 0.37 (22.5% of 1.62 MAF) and other return flow was 0.08 MAF (20% of 0.45 MAF).

PatFeeder Canal system was commissioned in 1969, the canal 171 km, distribution length  953 km  and has a discharge   of 6700 cusecs. The canal system has a command area of 508,425 acres. Kirther Canal System, was built in 1932, the canal is 84 km, whilst the distribution system is 200 km long. The canals discharge is 2400 cusecs, whilst the command area is 266,000 acres. Uch Canal System was commissioned in 1901; it is 53 km long, with a discharge of 700 cusecs and a command area of 68,000 acres. Manuthi Canal System was commissioned in 1909; it is 23 km long with a discharge of 600 cusecs and a command area of 28,000 acres. Drainage system is 90 km long, with a discharge of 1200 cusecs, and total drain length of 1419 km, the catchment area is 555,972 acres.

                                                                                                                      
Dams
There have been various attempts to construct dams in the Province Hub Dam was built to supply water to Karachi and some agriculture use in Baluchistan, is a reservoir on the Hub River. It is situated 56 km from Karachi city in Karachi and Lasbela Districts on Sindh and Baluchistan provinces border. The dam is extended to 24300 acres with gross storage capacity of 857000 acre feet. It is the Pakistan's third largest dam. It is an important source that provides the drinking water to the metropolitan city Karachi. A dam was built in the Pishin area , called Bund Kushail Khan, in 1990 , this was silted up and is to be rehabilitated, the dam has a command area of 10000 acres , due to silting its capacity was reduced from 33800 acre feet to 9000 acre feet . Mirani Dam in District Kech, on  Dasht River south of the Central Makran Range   Its 302,000 acre feet (373,000,000 m ) reservoir is fed by the Kech River and the Nihing River. Mirani Dam was completed in July 2006 and began impounding the Dasht River in August 2006. While the dam is supposed to irrigate up to 33,200 acres (134 km2) of land according to official plans, only a fraction of this land is irrigated and developed, On the night between June 26 & 27, 2007 the backflow water from Mirani dam inundated upstream areas of Nasirabad, Nodez, and Kallatuk destroying several thousand houses, date trees, and indigenous underground irrigation channels.  Sabakzai Dam, Zhob District,  is an embankment dam on the Sawar Rud, a tributary of Zhob River, about 68 km southwest of Zhob in Balochistan, Pakistan.The 395 m long dam is earth and rock-fill with a command area of 7300 acres. Construction began in 2004 and it was inaugurated on 3 September 2007. The following are dams are under implementation: Toiwar/Batozai Dam District killa Saifullah; and Shadi Kaur Dam Pasni District Gwadar. A phased program of building 100 dams is also under active consideration.   Dams in the pipeline, WAPDA has prepared detailed Feasibility Studies of following dams which are in pipeline for implementation: Winder Dam District Lasbella; Hingol Dam District Lasbella; Noulang Dam District Jhal Magsi; Garuk Dam District Kharan; Pilar Dam District Awaran; Basol Dam District Gwadar; and Badanzai Dam District Zhob.
Rivers
The Province has a large number of rivers. The rivers are generally torrential or empheral which become active for a short period during limited heavy showers. Some of the streams get absorbed within the land or drain into depressions. Very few rivers remain active for a long time The River potential is summarized is as follows:

Basin
Water Available
Water Use
Balance Available
Dasht River Basin
660
83
577
Gaj River Basin
233
25
207
Gawadar - Ormara
546
64
482
Hamun-e-Lora
189
28
161
Hamun-e-Mashkel
2078
312
1766
Hingol River Basin
942
136
806
Hub River Basin
380
80
300
Kachhi Plain
1902
634
On the proballe direction of sub soil floew of water more wells every 1268
Kadanai River Basin
77
10
67
Kaha Basin
515
103
413
Kand River Basin
18
2
16
Kunder River Basin
103
27
76
Mula River Basin
338
43
295
Nari River Basin
817
126
691
Pishin Lora Basin
302
169
133
Porali River Basin
1106
237
869
Rakhshan River Basin
320
34
286
Zhob River Basin
267
110
157
Balochistan
10793
2223
8570

Kareez
Kareez is an indigenous method of irrigation in which groundwater is tapped by a tunnel. After running for some distance the tunnel comes out in the open and the water is conducted to the command area. In Pakistan it is confined to the province of Baluchistan. Karez is an old and stable irrigation system of Pakistan. It is a community enterprise managed by tribal tradition and run by social control. Kareez are only utilized in Baluchistan. Kareez are a underground , sub soil system of water flow ., these have been in use since last 3000 years and are possibly derived from similar practices in the Iranian arid lands .The residents mark an area where rainwater drained into an underground formation and some water appeared a few kilometers down on land floor . The residents dig a well down to the appearance of groundwater. This well is called the master well, water from which flows downstream. On a probable direction of sub soil water flow more wells are dug, every 50 to 100 meters apart. These constructions provide water for years..The discharge is between 0.5 cusecs to 3 cusecs. Water from kareez is dwindling mainly because of the use of tube wells

The indigenous management of systems predicated upon extremes. In Baluchistan, we have 6,000 years of cultural knowledge of droughts. Unfortunately, these indigenous systems of providing water have been replaced by unsustainable tube wells. The tube wells have sucked all the water out of the traditional karez system and have only made a few farmers rich while many others have become paupers. In fact, there has been a lot of migration from the area over time as smaller farmers lost their orchards, their status and their identity. 

Groundwater Potential in Baluchistan


Pakistan’s major groundwater resource is in the irrigated areas of the Indus Basin, while the second source lies in the areas outside the Indus Basin. . The groundwater outside Indus Basin is in Baluchistan province, where the recharge source is mainly precipitation i
The regions of the Province, which are underlain by unconsolidated sediments formed by the deposition of mountainous outwash from the surrounding highlands, have been divided into 12 distinct Basins, flood plains and valleys fills. The Province lies in the five hydrological zones namely, Mountain ranges, Piedmont plains, Valley floor, plains and rolling sand plains. The groundwater, in substantial quantities, occurs in unconsolidated aquifers in almost all basins and sub-basins. The groundwater resources in six basins of the province namely Hamune, Lora, Kachhi Plain, Nari, Pishin and Zhob have been assessed. The effective rainfall coefficient of 20% to the annual rainfall for the mountain areas is used to estimate rainfall of 1.21 MAF.

Water formations of the Province cab be divided into three parts ,About 70% area is mountainous , at the foot of the mountain starts a formation build by deposition of fissured, disintegrated and fragmented rocks transported by water . This formation contains layers of gravel, deposits of varitypes types of sand and clay lenses .Its permeability is high. It is water saturated to various depths. The surface floor is generally steep and near its end start finer deposits of clayey types, this has low permeability and water is found at shallow depths .There are many such valleys ,  these sources of water have been used since long . The total groundwater resource of Baluchistan Province was assessed as 2.13 MAF.

The Groundwater is extracted through open surface shallow wells as well as through deep tube wells .However the groundwater resources have extensively and indiscriminately been exploited during the past three decades which has seriously damaged the quantity and quality of the ground water aquifer resulting into the sharp annual depletion ranging from 13 meter in different water basins of the Province. The Provincial Government is taking remedial measures to augment the ground water table through adopting ground water recharge measures, ban on installation of new tube wells and capping of the subsidy on already installed tube wells.

Plans have been formulated to meaning full harvesting of huge flood water through construction of surface water body to shift acute pressure from ground water resource to the surface water bodies. In Baluchistan Province present groundwater abstraction has been estimated 0.45 MAF by about 24 000 private tube wells. The average capacity is 0.3 cusecs of private tube wells and 0.18 cusecs of pumped dug wells (ACE and Halcrow, 2001).


Year



Number
Annual Increase
1965
470

1966
650
180
1967
870
220
1968
1075
205
1969
1285
210
1970
1870
585
1971
2278
408
1972
2521
243
1973
3040
519
1974
3646
606
1975
4262
616
1976
4631
369
1977
4863
232
1978
5143
280
1979
5954
811
1980
6453
499
1981
7033
580
1982
7458
420
1983
7691
238
1984
7997
306
1985
7887
110
1986
7952
85
1990
11000
762
1995
17000
1200
2000
24000
1400

QESCO statistics report that by the end of FY 2015 there were 31139 electric tube wells in the Province.

Ground Water Balance

In certain areas of the province of Punjab and Baluchistan mining of groundwater has aggravated the situation. The water balance in Baluchistan presented as follows:

Parameters
Baluchistan
(MAF)
Rainfall Recharge
1.21
Recharge from Canal System
0.29
Return flow from irrigation
0.37
Domestic & industrial return flows

Other return flows
0.08
Recharge from Rivers
0.18
Total
2.13
Groundwater  Abstraction  (Private,  STWs  & PTWs)
0.45
Groundwater      Abstraction    (domestic    & industrial)

Non-beneficial ET losses
1.13
Sub-surface Outflow/change in GW
0.41
Base flow to Rivers
0.14
Total
2.13

The above Table reveals that the groundwater resources for Baluchistan are 2.13 MAF. About 0.45 of groundwater is being extracted. This indicates that a groundwater potential of 1.69 MAF is more available for the Province. However, 0.67 MAF of that potential resource is linked to the canal system in the east of the Province where the groundwater is generally saline. The remaining potential for the rest of the Province is 1.02 MAF. The sustainable groundwater development in the Province is 0.64 MAF (ACE and Halcrow, 2001), with 50% of this potential located in two basins of Porali and Hingol. The situation has worsened in a number of sub-basins since 1996 as the uncontrolled development of groundwater in the Province was allowed to continue. Some sub-basins within the Province (Quetta, Mastung, Mangochar and Pishin in the Pishin-Lora basin, Loralai, and Duki in the Nari basin) are rapidly approaching a catastrophic state in terms of groundwater resources and urgent action is needed to prevent. Thousands acres growing garden and vegetable crops in Loralai Basin have become barren due to the drying up of the aquifer.

Ground Water Management

One of the reasons for higher exploitation of groundwater was the flat-rate cost of energy charged to the farmers. Therefore, it is necessary that energy charges should be proportional to the actual use of energy. Because of the absence of groundwater management in the private sector, anyone can install a  tubewell anywhere in his land and can extract whatever amount of water he wants any time without consideration of the detrimental effect of his action on the resource. If the pumping is equal to recharge rate for a sufficient period of time, the watertable depth will stabilize somewhere below the ground surface. In cases where the pumping of groundwater is in excess to the potential recharge rate, the mining of the aquifer will result in the accelerated depletion of the groundwater resource with an unsustainable lowering of the water table. Also, the uneven groundwater development and pumping through private tubewells has started showing stress on the aquifer in the form of excessive draw-down and deterioration of groundwater quality. This requires serious attention and the urgent adoption of measures for proper groundwater management.

A groundwater regulatory framework should be introduced and implemented for the sustainability of groundwater use. Recharge of groundwater should be increased by increasing canal diversions, rainwater harvesting and check dams. Continuous over-draft in excess of the average annual recharge has been resulting in the knocking out of shallow pumping wells. More pumping in relatively dry years, like nowadays, is causing excessive draw down in certain areas. As a result, at the present time, about 5% area of Punjab Province and 15% of Baluchistan contains groundwater which is out of the reach of the poor farmers. This is likely to increase to 20% in Punjab and 30% in Baluchistan in the next 25 years, with the present growth of groundwater withdrawals and unsystematic pumping of fresh groundwater due to abnormal lowering of the water table and an increase in areas adjoining saline zones. In an effort to manage the increasing demand for water, low water delta crops should be preferred on high delta crops and more efficient irrigation methods should be used. In addition, there is a large area of the Indus Basin which has marginal and saline groundwater. This water can be used for saline agro-forestry and alternative agricultural crops.

Conclusions related to ground water


1.     Groundwater has become a major source of water supply in Pakistan
2.  Excessive use of groundwater is causing secondary salinisation
3.  The situation has worsened in a number of sub-basins in Baluchistan Province due to groundwater mining
4.     Continuous over-draft has resulted in excessive groundwater abstraction 15% of Baluchistan Province contain groundwater out of reach of poor farmers

5.  There is a need to realistically estimate and manage the demand for water
6.     The flat-rate energy charge has encouraged farmers to exploit more and more groundwater, which has resulted in an unsustainable situation.




Recommendations related to ground water


1.       A  groundwater  regulatory  framework  should  be  introduced  and  implemented  for  the  sustainability  of groundwater use
2.  There is need to manage the demand of water
3.  Low water delta crops should be preferred to high delta crops
4.  Efficient irrigation methods should be used to irrigate crops
5.     Recharge of groundwater should be increased by increasing canal diversions, rainwater harvesting and check dams
6.  Saline water can be used for saline agro-forestry or for alternative agricultural crops
7.  Energy charges should be proportional to the use of energy for tube wells
8.  Research on groundwater recharge is urgently required.

 
Proposed Quetta Project
Quetta city is located in a valley of about 700 sq. miles, It us circumcised by ranges of dry mountains at the foot of which exists the flat residential land. The valley receives 8.75 inches of rain every year; about seven months are completely dry .The whole area has no perennial source of water. Ground water has always been the main source of supply Attempts have been made to construct storages and to divert rain water in the near past an underground aquifer was discovered which was used to supply Quetta City this also is now nearing depletion and the water supply to Quetta City is seriously threatened.
The government of Baluchistan intends to embark upon an ambitious plan of providing water to Quetta from Pat Feeder and Kachhi canals through a 271-km-long pipeline The total cost of the project has been estimated at Rs40 billion (56 per cent of the current Public Sector Development Plan Rs 71bn) and it is scheduled for completion in three years.
The pipeline, with a diameter of 56 inches, will run from Naseerabad to Quetta. It will pass through the districts of Lahri, Sibi, Kachhi and Mastung areas which feature plains as well as mountainous terrain. The project envisages pumping of 120 cusecs of water with the help of eight pumping stations from a height of 350 to 7,000 feet above sea level.

Another question, and a technical one, is that how 120 cusecs will be pumped from a height of 350 feet to a height of 7,000ft with the help of eight power stations on different sites. the pumping stations will either be powered with the help of fuel-fired generators or solar energy or a separate power house having a capacity of 100 megawatts will have to be set up.  Sixty million gallons of water per day (MGD) are needed for Quetta`s two million people while the combined projected output of the three dams would be, at best, 35MGD.
 
Artificial Recharge

.Groundwater recharge or deep drainage or deep percolation is a hydrologic process where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. This process usually occurs in the vadose zone below plant roots and is often expressed as a flux to the water table surface. Recharge occurs both naturally (through the water cycle) and through anthropogenic processes (i.e., "artificial groundwater recharge"), where rainwater and or reclaimed water is routed to the subsurface. If waterfalls uniformly over a field such that field capacity of the soil is not exceeded, then negligible water percolates to groundwater. If instead water puddles in low-lying areas, the same water volume concentrated over a smaller area may exceed field capacity resulting in water that percolates down to recharge groundwater. The larger the relative contributing runoff area is, the more focused infiltration is. The recurring process of water that falls relatively uniformly over an area, flowing to groundwater selectively under surface depressions is depression focused recharge. Water tables rise under such depressions.

The sediment content of Baluchistan Rivers is very high, clay and silt forms more than 50% to 90% of the sediment transport.. High clay and silt are harmful for storages and dams .Construction f check dams were utilized in Baluchistan to recharge the ground water. The main purpose of these delay action dams wd to store rain and flood water , which over time percolated into the groundwater formations .Large number of such dams were constructed , these functioned well in the first few years but then were clogged  by the high silt and clay load . Another method tried was to spread surface water thinly so as to recharge the underground storage, this also did not work well
  Building multiple storages on the same river is suggested also suggested is to have a main dam which would be clogged n-but a side opening allowed water to be stored in a side storage facility .

Reuse of waste Water

Quetta valley needs to consider the use of treated and recycled waste water. Reclaimed or recycled water is the process of converting wastewater into water that can be reused for other purposes. Reuse may include irrigation of gardens and agricultural fields or replenishing surface water and groundwater (i.e., groundwater recharge). Reused water may also be directed toward fulfilling certain needs in residences (e.g. toilet flushing), businesses, and industry, and could even be treated to reach drinking water standards. This last option is called either "direct potable reuse" or "indirect potable" reuse, depending on the approach used. Colloquially, the term "toilet to tap" also refers to potable reuse.
Reclaiming water for reuse applications instead of using freshwater supplies can be a water-saving measure. When used water is eventually discharged back into natural water sources, it can still have benefits to ecosystems, improving stream flow, nourishing plant life and recharging aquifers, as part of the natural water cycle
Wastewater reuse is a long-established practice used for irrigation, especially in arid countries. Reusing wastewater as part of sustainable water management allows water to remain as an alternative water source for human activities. This can reduce scarcity and alleviate pressures on groundwater and other natural water bodies
Wastewater treatment typically includes preliminary treatment steps in addition to primary and secondary treatment. Preliminary steps include measuring the flow coming into the plant, screening out large solid materials, and grit removal to protect equipment against unnecessary wear. Primary treatment targets settle able matter and scum that floats to the surface
Secondary treatment processes are employed to remove total suspended solids, dissolved organic matter (measured as biochemical oxygen demand), and, with increasing frequency, nutrients. Secondary treatment processes usually consist of aerated activated sludge basins with return activated sludge or fixed-media filters with recycle flow (e.g., trickling filters; rotating bio-contactors), followed by final solids separation via settling or membrane filtration and disinfection 
Advances over the past 20 years in membrane bioreactor (MBR) technologies have resulted in an alternative to conventional activated sludge processes

Reasons for water scarcity

 
The reasons for water scaricity are : Geographic Location ;Low Rainfall ;Geo-Morphological Characteristics ; Global Warming Climate Change & its Impacts (Drought, Flooding Sea level raise) ; Poor Watershed Management / Watershed degradation. ; Traditional Cropping Pattern / Irrigation Systems (Flooding of field) ; Rapid Growth in Population/Urbanization ; Poor Mass-Awareness ; Poor legislative frame works and its Implementation.



Water availability in Baluchistan has always been remained deficient against the demand, as per UN standers availability of 30 gallon water per capita is ideal arrangement but in Baluchistan hardly 10 gallon of water per capita is being made available to about 60% of population. In-efficient use of the available surface water resources, in-discriminate exploitation of the ground water, wastage of heavy flood water, watershed degradation, coupled with the phenomenon of climate change leading to extreme events of flood and drought has made water management a difficult mandate.

Despite huge interventions in water sector, population growth urbanization,           development of the mining, industrial sector and expansion        in agriculture activities the water demand has increased, putting great stress on the water resources of the province which are otherwise in deficit due to peculiar environment of the region.
The province of Baluchistan has suffered long drought spell of 8 years from 1997-2005 and also three continual high intensity cyclonic, river an and excessive rain floods in 2007 2010, 2012 having divesting impacts on all social sectors but more pronounced on water sector.

 Steps needed to be taken

Since attaining provincial status, no water policy could have been formulated, The province  needs to  ensure adequate and sustainable water resources (by 2030) through holistic development and efficient management of available and new water resources. Activities and steps that are needed to be taken are :
Rain water harvesting through efficient water shed management.

Ban on uncontrolled with drawl of ground water.

Improvised cropping pattern, suiting to environment and Water situation of the Province.
Use of spate Irrigation (Sailaba and Khushkaba).

Introduction of efficient irrigation technology.

Efficient plan and development of water budget to meet the requirement of different sectors as actual requirements basis
Check on massive Rural Migration to Urban Centers

Check on development and industrialization in the Piedmont Region of the Valleys

Behavioral Change in the Community.

Effective measures against water losses  and  equitable distribution of water amongst beneficiaries.

Identification of technically feasible and economically viable and community oriented schemes through professionals and timely completion of the projects for effective harnessing and dividend generation from water recourses.

Institutional reforms and capacity building to make the organization and professionals equally dynamic and responsive future challenges ahead for assured sustainability of water resources

Address of Inter Provincial Water related issues (water sharing, drainage and flood related issues).
Institutional reforms, capacity building through advance learning and research at all the levels stakeholders to ensure, effective response against the challenges

Water Policy
The provincial Irrigation Department has formulated the provincial water policy the basic documents of water policy are approved by Provincial Cabinet. However unfortunately the same is not transformed into an Act.
The policy is aimed at to achieve the fallowing aims and objectives.



Efficient conservation and management of the available water resources.

Maximum harnessing of the flood and rain water through efficient water shed management and development of surface water bodies.

Efficient Ground Water recharge measures to arrest sharp depleting ground water levels Quetta, especially in Pishin Lora, Nari and Porali basins.

Increase of ground water exploitation in the areas of Dasht, Rakhshan, Human Mashkhail and Hingol river basins where potential exist
Steps Initiated

The Federal government through the efforts of Provincial Government has approved a PC-II for detailed feasibility study of water resource development through construction of Medium Storage Dams in Balochistan and allocated Rs.100.0 million in the Federal PSDP for financial year 2013-14. Consultants are being hired
Consultants have been hired to undertake Detailed Feasibility Study for construction of Dispersal Structures on Zhob River for gainful utilization of huge quantity of water which is being wasted due to the non availability of infrastructures. As a result of Detailed Survey/Investigation a Proposal for Construction of Dispersal Structures of Zhob River costing Rs.10.0 Billion have been prepared and being processed for approval of the competent authority.

The World Bank financed Project BSSIP (Baluchistan Small Scale Irrigation Project) has already engaged consultants for the detailed feasibilities of integrated water resource management of Nari and Porali Basins at a cost of Rs.17.0 Billion and 13.5 Billion respectively.

The PID Baluchistan has recently rehabilitated 15 karezes in District Pishin, Killa Abdullah, Mastung and Kalat Districts through a World Bank financed Baluchistan Small Scale Irrigation Project (BSSIP) at a cost of Rs.550/- million with cleaning, extension, lining of conveyance system and construction of check dams upstream to help recharge of the karez

Rain water harvesting



The growing demand of water against the scarce water resources is the one of the biggest challenge of 21st Century as the regular water supplies through conventional system is on   decline and rain water harvesting can thus prove as an important alternative and supplementary resource. Through efficient rain water harvesting practices the short supplies can be augmented both in the rural and urban centers.

Rain water harvesting is low cost simple technique easily practicable with to supplement the scarce water resources and as a better alternative against the brackish ground and polluted surface water.. In the arid and semi arid region the rain water practices are rather          more important to collect it as efficiently as possible otherwise the rain water resource available may be lost through surface run off and evaporation
During the past decades the rain water harvesting is actively introduces in the rural and urban areas and as gainpopularity being accessible, affordable and relatively clean source at the domestic / local level.
Owing to the pollution of ground water and surface water, water scarcity, increase in the population the available water resources are dying up as such the communities have to tune up themselves to new resources through rain water harvesting practices.

Rain water harvesting practices are observed as of great importance in the arid and semi arid regions and in the areas of small coral volcanic islands, remote and scattered human settlements
Rain water harvesting is defined as method of inducing, collecting, storing     and conserving local runoff for house hold, drinking, livestock   as well as for small scale agricultural activities  in  the arid and semi arid regions. The rain water harvesting practices are mostly adopted practiced in the arid and semi arid zones with the limited annual rain fall, where rain    water harvesting i.e. use of surface  runoff  can  be  a potential source to supplement to address water scarcity issues.

Rain water harvesting in the arid and semi arid region is illustrated by micro catchment area measuring few hundred square meter with adjacent         basin area where runoff is stored and conserved for consumption of trees and bushes and also for the consumption of small local population.


Rain water harvesting technology is quite simple for collecting rain water from roof tops catchment, land surface catchment with the conveyance system for transfer of rain water to be collected in the storage tank

In different parts of Asia the Governmental and non-government Organization       are involved in rain water harvesting particularly in Thailand      and Philippine both the Governmental and community organization as well as through house old based initiatives the use of rainwater harvesting technology is expended particularly in the water scare region
Rain water harvesting is accepted has viable practice for augmentation of        fresh water as the bacteriological contents of the rain water collected from the small catchment is less and also the quality of water harvested from the properly maintained roof tops catchment connected with the storage tank having better covers is preferable for drinking purposes as such rain water harvesting practices are widely acceptable.

Rain water harvesting is equally suitable in the urban as well as rural areas at its augments Municipal Water Supply for house hold and drinking water purposes as it does not requires highly skill manpower .

The rain water harvesting technology and practices are highly cost effective which depend of the type of catchment, conveyance and storage tank and material used.The cost of rain harvesting technology and arrangements is for less than cost involve in the development of shallow dug wells, tube wells and also does not involve huge O&M cost; The feasibility and efficiency of the rain water system harvesting in a particular locality depends on the amount and intensity of the rain, the length of catchment area and  the gradient/slops of the micro catchment area. These variables can however be adjusted according to the house hold requirement and needs in particular area


Benefits


The benefits of rainwater harvesting include : Improvement in the quality of ground water; Rise in the water levels in the wells and bore wells that are drying up; Mitigation of the effects of drought; Attainment of drought proofing; An   ideal solution to water  problems in areas having inadequate water resources; Reduction in the soil erosion as the surface runoff is reduces; Decrease in the choking of storm drains and flooding of roads ;Saving of energy to lift ground water (one meter rise in water level saves 0.4 Kilowatt hour of electricity); rain water harvesting technology are simple to install and operate;  Common people particularly in the rural area can be easily trained in the rain water harvesting practices. The construction material required are cheap and radials available and it is convents that it provides water for consumption at the spot; The maintenance is also quite cheap and simple which involves periodic cleaning of the tanks regular inspection      of the conveyance system; The main objectives of rain water harvesting is purposeful utilization of available       rain water to meet the local requirements without much financial implications; Rain water practices are highly helpful in the areas facing water scarcity and facing threats of drought or drought like situation ;Rain /flood water harvesting reduces the cast of portable water being less cost incentive; Rain flood water harvesting reduces pressure on already under stress ground water resources and raises ground water table ; Soil erosion due to heavy flesh floods in the river bed can be reduced through rain/flood water harvesting ;Rain water harvesting reduces accumulation of salt in the soil which is harmful to the growth of plants and allow better root growth and also increases drought resistance in plants.
Disadvantages

Rain water harvesting has benefits but there are also some aspects that need attention, these are: The major disadvantage to the rain water harvesting technology is the limited and un-certain rain falls;   the technology assists the poorer sections of society  who are unable to attract the attention of authorities; Ground slopes are main limitations defeating efficient rain/flood water harvesting           in particular areas of high/medium altitude mountain ranges where gradient/slope is high, greater than 5%; In the areas with uneven surface and uneven distribution of runoff huge earth works get involve having financial implications hence unfeasible for the local formers; The texture of the soil of the local area is again very important, soil with high quantity of sand and gravel the most permeable formations allow high infiltration as compare to the intensity and number/intervals of rains and runoff.

Rain harvesting possibility in Baluchistan  
The rain water harvesting possibilities in Baluchistan is influence by the following factors : The climate of the province ranges from semi arid to arid with extreme variation in the temperature , the mean annual precipitation varies from less 50mm to more than 400mm in the valley;  Most of the precipitation is received in the higher mountain during the winter between 250 mm to 350mm;  Due to high gradient and slopes the rain water usually flow in flesh down the stream and as such rainwater harvesting practices are opted in the low plains mainly through construction of micro bundates and pit holes for the limited  local consumption onomadic population; In the given geographical, geomorphologic and climatic conditions the rain water and flood water harvesting are more relevant and important in the context of the province which facing serious challenges of water scarcity for progression in different social sectors; Due to limited rains and deficient availability of surface and under ground water resources            out of 30.00 million acre cultivable land only 4 .00 million acre of land is   put under cultivation which hardly 7% of the geographical area of the province 44%; Out of total cultivated area of 4.00 million acre 47% of the cultivable land is irrigated whereas 53% of the remaining cultivable land is under Sailaba and Khuskaba irrigation using flood and rain water resources; The land under Khuskaba farming is 0.26 million ha about 12% of the total cultivated land; Khuskaba irrigation is traditional system of farming irrigated through local runoff from the adjacent catchment; In the   centre and north-east of Baluchistan Province seven districts are defined as highland rained  areas.  These districts are Quetta,            Kalat, Pishin, Loralai, Zhob, Kachi and Khuzdar . these have a total geographical area of 14.9 million hectares; In Balochistan, runoff farming system in named as Khushkaba and it goes back as early as 3000 BC and provided economic basis for some of the early civilizations; These systems are located in highlands of  Khurasan  Range,  on eastern slopes of  Suleiman  Range  and  Central  Brahui  Range  which are characterized as temperate, where precipitation is gentle and spread over a longer period; Rain fed Khushkaba system depends upon direct rains. The farmers sometimes develop a small catchment area on upper side of the field and the rainwater is harvested for farming on the lower side; sometimes no catchment area  exists and the water is directly harvested in the cultivation fields; The major agricultural crops of these rain fed districts are wheat, tobacco, potato, apple, grape and barley. Farming in the district is mostly rained (Barani);  The scarcity of water in these district calls for adopting comprehensive water harvesting and management strategies, in order to meet the demands for agricultural and domestic water needs, which can be met through; Rain Water Harvesting for storage for future local / domestic use; Rain Water Harvesting as Ground Water Recharge measures; The Rain water is so harvested by adopting traditional techniques and construction of surface and underground structures.

 Rain Water schemes implemented


The Provincial Irrigation Department has undertaken different projects for rain water harvesting at the cost of Rs.369.00 million for the last three years with the details as below:-


S
#
Fin. Year
Name of Scheme
No
.Cost (Rs.M)
1
2010-11
Construction of MICRO Bandat for Agriculture District Harnai
50
30.00
2
2010-11
Strengthening and raising of Zamindara MICRO Bandat in Dureji area District  Lasbella
10
10.00
3
2011-12
Construction of Small MICRO Bandats at District Gwader
100
100.00
4
2012-13
Construction of MICRO Bandats District Musa Khail
60
65.00
5
2012-13
Small Irrigation Schemes (Bandats) in Musa Khail
140
153.985
6
2013-14
Construction of MICRO Bandats District Kech
130
149.00
7
2013-14
Constt: of MICRO Zamnidara Bandats District Kech
20
15.40
8
2013-14
Construction of MICRO District Jhal Magsi
50
60.00
Total:
560
583.385

Baluchistan Experience with Recharge Efforts


 
Groundwater mining in Baluchistan is recognized to be a very serious problem facing the water sector. It is therefore not surprising that numerous efforts have been undertaken to cope with the alarming situation of depleting water tables. A number of projects have been undertaken in the past. A very promising and good project was the Zargai Recharge Project established by Balochistan Minor Irrigation and Agricultural Development Project to evaluate the viability, both technical and economic of the off-line aquifer recharge scheme. It consisted of three components, a diversion structure, a storage reservoir and a recharge area. The recharge area consisted, of a series of zigzag channels through which the rainwater flows slowly and with time infiltrating into the ground.

Results of the study indicated that infiltration is related to the depth of ponding and that the optimal depth of ponded water to maximize the recharged is 150 cms. It was found that a net yearly infiltration volume of 120 cm takes 10 years to reach a 100-meter deep groundwater table in a silty loam soil, but only 5 years in the same soil with 60% stones. It was concluded that the artificial recharge schemes in Baluchistan had an insignificant impact upon falling of groundwater levels, and were likely to contribute, an amount of additional water capable of supporting less than 1.5% of the existing orchards in the project area. The project is now dead.

The experience with delay action dams, an excellent technique, has not been a very good one.  The high amounts of sediments and silt load brought in by the feeding streams in the reservoirs has been the major factor in reducing the effectiveness of the dams as sources of recharge. It is essential that the dam design may be radically revised to include provisions for allowing water escapes on the downstream side of the dam body to recharge the bed of the stream. In the existing dams provision for releasing water can still be provided by installing siphon tubes system on each dam.

Watershed management is another area where little has been done in the province. Major efforts are required to undertake watershed management works in potential areas with adequate soil covers. All future dam projects must have adequate provision for watershed management.









It remains to be seen how effective the recent efforts to recharge aquifers in Baluchistan by constructing leaky dam (as done by PCRWR near Quetta) are successful. It is however, essential that an integrated approach be made to recharge and conserve water. 

We should save the karez system where we can… it provide the cushion that keeps farmers anchored to their community. The karez system has been tried and tested for thousands of years and given the threat of climate changeparticularly in a land like Baluchistan, it is now more relevant than ever.

Update Jan., 4, 2019:
A Senate Panel on Thursday demanded Rs9 billion collected for construction of multi-billion dollar Diamer-Bhasha and Mohmand dams to be diverted for development of a series of small dams in Baluchistan to support agriculture and livestock sectors and create job opportunities. The meeting was informed that the construction of 100 small dams in Baluchistan involved five packages. In the first package (2008-2013) 20 dams were completed at a cost of Rs2.4bn, while in the second package (2013-18), 22 out of 26 dams have been completed at a cost of Rs4.4bn whereas in the third package 20 more dams are scheduled to be completed by 2020 at a cost of Rs7.6bn.In the fourth and fifth packages, 23 and 11 dams respectively, would be built by 2026.The meeting was further informed that total irrigated area of 66 dams built under the first three packages was 2,154 million acres whereas total storage capacity of these dams was around 2,467m acre feet. The committee was informed that the release of funds for the small dams was very slow. The committee asked the planning ministry to consider increasing the number of small dams in Baluchistan from current100 dams to 500 dams in five years.