INITIATIVES AND TECHNOLOGIES FOR RAIN WATER HARVESTING IN UTTAR PRADESH

(An Urban perspective)

R.S.Sinha Ground Water Expert

State Water Resources Agency, U.P., Lucknow

INTRODUCTION

Ground water is perhaps the most neglected, poorly managed, unregulated & over-exploited natural resource in the state of Uttar Pradesh. However, the contribution of this resource in various water sectors of the state can not be overlooked and its significance can be evaluated by the fact that ground water is providing about 75% of the irrigation supplies, 80-90% of the drinking water supplies and fulfilling almost all the industrial needs, but despite the growing importance, the regulatory & management requirements for protecting & conserving ground water have never been suitably recognized and not given any serious thought so far in the state. On one hand, the development of ground water has become an imperative need of the state, as the demand of this resource is increasing in multiple proportion particularly in minor irrigation programs and also in drinking water & industrial sectors, while on the other hand, ground water resource management & its control and regulation, especially in overexploited and critical areas, is also becoming the ‘need of hour’, so as to conserve & protect this resource. Hence, the development as well as the conservation of ground water resource, at the right time & at the right place, becomes essential for sustainable and equitable economic growth of problem areas. AN INVISIBLE RESOURCE

• Ground water resource is a distinguished and vital hidden component of ‘Water Cycle’ and therefore, scientific approach is needed for its comprehensive understanding as far as development & use of ground water and its conservation related to Rain Water Harvesting is concerned.

• Leonardo de Vinci has envisioned this invisible resource as the greatest river of the earth flows underground, so the need is to understand its dynamics.

DEPLETING URBAN GROUND WATER IN U.P. - TIME TO ACT

Uttar Pradesh is urbanizing at a faster pace and so the urban water supply demand is also

escalating with increasing population. In most of the cities, as surface water sources are not adequately available, there is tremendous pressure on ground water resource to fulfill the drinking water requirements.

In Lucknow city, despite river Gomti being a major source for drinking water, about 60% municipal water supplies are now dependent on ground water, while in most of the other urban centers, 80-90% of drinking water demand and even whole municipal water supply is now being met through tube wells & hand pumps, making ground water a predominate source for water supplies of urban areas. This clearly reflects the increasing contribution of ground water in urban water supplies, in spite of the fact that this resource is rapidly depleting within a transforming concrete urban environment.

There are overall 630 major and small townships in U.P. and majority are located on alluvial aquifers of Indo-Gangetic plain, where due to easy accessibility, private tube well construction activity, especially in multistory buildings & housing colonies, is going on unchecked and as a result, dependency on ground water for drinking & allied purposes, especially in big cities have mushroomed.

1.69

1.13

1.10

1.06

1.01

0 0.5 1 1.5 2

Gomti Nagar

Vikas Nagar

Indira Nagar

Hazratganj‐Narhi

Cantonment

HOTSPOTS (where Ground Water Level is declining  at an alarming  rate)

Decline (m/ year)

But, as the unscientific & unregulated ground water extraction in urban centers is almost reaching to unsustainable levels and even to irreversible stage, the emerging trends of exploitation are very disturbing. Especially, in the absence of effective management interventions, the impact may be extremely grave for the urban environment of the state and therefore, the rapid depletion of urban aquifers may lead to critical situations. There are no authentic studies, which could help in evolving some strategic plans for suitably managing, protecting & conserving Urban Aquifers in order to make them sustainable for future ground water extraction. DECLINING TREND

The available data of groundwater levels being monitored in some urban areas of U.P. indicate a declining trend, even to alarming levels as observed in Lucknow city. The bar diagram depicts annual average groundwater level decline in major cities of the state.

HOTSPOTS OF LUCKNOW CITY Following are some of the Hotspot of Lucknow city, where groundwater levels are continuously going down at a much faster rate

URBAN POPULATION Size of urban population is continuously increasing in Uttar Pradesh. The following table

shows decadal changes in urban population of the state. The point of concern is that to meet such rising demand of urban populace, drinking water

demand is also growing; therefore ground water resources are being extracted to unsustainable levels.

CENSUS YEAR POPULATION (MILLION)

PERCENTAGE OF URBANISATION TO TOTAL

POPULATION STATE TOTAL

URBAN

1971 88.34 12.38 14.02 1981 110.86 19.9 17.95 1991 139.1 27.6 19.84 2001 166.05 34.5 20.77

RAIN WATER HARVESTING & GROUND WATER RECHARGE Its a simple traditional concept of conserving rain water in areas of scarcity or depleting

ground water. Harvesting of rain water means storing run-off on the surface or diverting it into ground

water reservoir through various artificial ways & methods based on scientific principles. The technology is economical & eco-friendly and for the welfare & benefit of mankind. It is an ideal solution for water problem areas. Its a proven method based on scientific guidelines to revive the depleting aquifers.

INITIATIVES & ACTIONS TAKEN IN UTTAR PRADESH

In Uttar Pradesh, though the State Government has felt the need of ‘Rain Water Harvesting & Ground Water Recharge’ (RWH & GWR) in the problem areas of the state to rejuvenate the depleting aquifers, but due to lack of institutional mechanism, the various line departments have not shown any serious commitment so far to carry out the rain water harvesting programme as per the geo-scientific norms. However, the concept of ground water conservation have been initiated in the state and for the last 7-8 years, various schemes & projects on RWH & GWR have been started & implemented (though in isolation) and the programme is still underway but the impact is still not known and its efficacy is yet to be established especially in alluvial aquifers of U.P. Various important initiatives & policy decisions, envisaging suitable provisions for rain water harvesting, have been taken at government level. The main initiatives include various provisions for roof top rain water harvesting, ponds, checkdams, on farm activities in both rural & urban areas, besides provisions for monitoring, co-ordination & implementation.

For urban areas of U.P., rain water harvesting has been made mandatory for all new housing schemes & Group Housing schemes with Combined Recharge System as well as for individual plots of 300 sqm & above.

Necessary amendments have been made in building by-laws. The initial decision in this regard was taken in the year 2001 and subsequently various

provisions/amendments have been made. Separate provisions for government buildings (both new & old) have also been made,

where installations of rain water harvesting is now compulsory. Provisions of water bodies, development of ponds in housing schemes.

Developing roadside pavements as potential by keeping them kaccha Recharge Areas has been highlighted in different government decisions.

But, despite such useful initiatives, the implementation process is so far rather slow & inadequate.

DECISIONS TAKEN FOR NEW HOUSING SCHEMES

Conserving existing ponds / reservoirs in new housing schemes. Provision of 5% land for water body. Depths of Ponds – maximum 3 mts (Identify natural catchment & feasibility assessment). In parks, only 5% area be covered with concrete / pavements. Foot paths / tracks be provided with permeable / perforated blocks. Pavements should not

be concrete. ‘Recharge Shaft’ should not to be constructed in ponds where risk of industrial/other

pollution may occur. Direct recharging of rain water to the aquifers from open/paved/unpaved areas

through recharge wells/ injection well (parks per field) is not permitted (as per G.O. dated April,2006).

ROOF TOP RAIN WATER HARVESTING (POLICY DECISIONS)

In lay- out plans of (newly/ proposed) Group Housing schemes (Govt./Pvt.), separate

network of pipes for combined RWH / recharging system be provided.

Vide G.O. Dated 01-07-08, Housing department, GOUP, has modified the initial provisions of RWH, wherein recharging system made compulsory for plots of 300 sq.m. & above.

GOVERNMENT/ SEMI GOVERNMENT BUILDINGS

Installation of RWH/GWR structures is made compulsory for all Government/semi Government buildings in the state.

POLICY DECISIONS FOR INDUSTRIES For Ground Water Level/Quality monitoring, piezometers made compulsory for industries.

Rain Water Harvesting: All industries, including existing and new, which are drawing

ground water shall mandatorily undertake artificial recharge measures.

OTHER SIGNIFICANT POLICY INITIATIVES/DECISIONS

Other significant policy initiatives/decisions taken by the state government include:- Constitution of high level ‘Executive committee’ under the chairmanship of the chief

secretary to review the rain water harvesting programme in the state. Declaring Ground Water Department of the state as ‘Nodal Agency’ for ground water

management, regulation & recharging in U.P. Constituting district level Technical Coordination Committees under the chairmanship of

District Magistrates for monitoring & implementing recharge activities. To create mass awareness, 10th June has been declared as ‘Ground Water Day’. Rain Water Harvesting has been introduced as a chapter for 6th to 8th class in the state.

PROPOSED GROUND WATER ACT

The U.P. government is seriously considering the imposition of ground water legislation in the state.

Bill has already been drafted and put on website for public opinion. The draft bill is under finalization.

Separate provisions are included for Urban, Rural and Industrial areas with focus on ground water conservation/ rain water harvesting.

RAIN WATER HARVESTING: AN AREA SPECIFIC / SITE SPECIFIC ISSUE

Rain Water Harvesting is an AREA SPECIFIC CONCEPT based on certain scientific norms and local conditions. This technique can not be standardized for different conditions. ‘Hydrogeology’ is the most vital component of RWH, providing base line informations for

planning, designing and implementation of Rain Water Harvesting & Ground Water recharge programme in an area. Locations feasibility. Rainfall data. Lithological configuration (based on strata chart of nearby borewell, design of

recharge well can be finalized) Water level decline & depth to ground water. Magnitude of ground water extraction. Status of ground water resource. Qualitative & quantitative aspects.

As the state of U.P. is characterized by the diversified hydro-geological situations,

elaborate and separate ‘Technical Guidelines’ for taking up the rain water harvesting recharge programme in the state have been issued for urban, rural & industrial sectors for the compliance & execution.

GUIDELINES

As per the Guidelines, the recharge schemes should only be taken up in those alluvial areas where depth to post monsoon water level is more than 8 mbgl with yearly decline of more than 20 cm. in pre monsoon period.

For Bundelkhand- Vindhyan, the limit for depth to water level is reduced to 5 mbgl. Further, provisions & guidelines for maintenance of recharge systems & impact assessment

of rain water harvesting schemes have also been issued. The other components of guidelines have been discussed in detail in the guideline document issued by the Ground Water Department of the state.

ROOF TOP RAIN WATER HARVESTING IN URBAN AREAS

METHODS / TECHNIQUES

Recharge Pit Recharge Trench Recharge Well / Injection Well Recharge Shaft Ponds/ Reservoirs Surface Storage (The benefit of roof top rainwater harvesting can be assessed by the fact that from Roof Top of 100 sq mt area with annual rainfall of 1000 mm, 80,000 litre rain water may be conserved / recharged every year)

METHODS FOR RAIN WATER HARVESTING IN INDUSTRIAL AREAS

SUGGESTED METHODS Recharge Pits Recharge Trench Surface Storage/Ponding (In any case, ‘Recharge Well/ Injection Well’ method should not be adopted in the industrial areas).

SURFACE STORAGE TECHNIQUE

RWH through roof top & surface pavement

AVAILABLE RAIN WATER FROM ROOF TOPS FOR RECHARGING The rain water available for groundwater recharging from the roof top catchment can be computed as follows:

A x R x C A = Roof Top area B = Quantum of Rainfall C = Run-off Co-efficient

Catchment Run-Off Co-efficient Pucca Roof 0.80 Roof of Tin/ Asbestos shade 0.85 Surface pavement/ unpaved area 0.60-0.70 For Pucca Roof, following computation is made: If Roof area is 100 sqm and rainfall is 1000 mm, the rain water harvesting potential & available rain water can be computed as follows:-

Total availability of Rain Water = A x R = 100 x 1000 1000 = 100 cubic meter, or 1 Lakh Litre Expected Recharge Potential = A x R x C = 100 x 1000 x 0.80 1000 = 80 cubic meter, or 80,000 Litre

QUANTUM OF RAINFALL FOR RECHARGING

The quantum of rainfall, which can be recharged/ stored annually, will depend on the catchment (roof area) & annual monsoon rainfall, as computed below:-

Roof Area

(Sqm) Annual Average Rainfall (mm)

300 400 500 600 800 1000 Quantum of Rain water available for recharge/ storage (mm)

50 12 16 20 24 32 40 80 19.2 25.6 32 38.04 51.2 64 100 24 32 40 48 64 80 150 36 48 60 72 96 120 200 48 64 80 96 128 160 250 60 80 100 120 160 200 300 72 96 120 144 192 240 400 96 128 160 192 256 320 500 120 160 200 240 320 400

1000 240 320 400 480 640 800

WATER STORAGE CAPACITY OF RECHARGE TANK/ FILTER CHAMBER For the areas receiving different monsoon rainfall, water storage capacity of recharge tanks & filter chamber will vary depending upon the roof area catchment. An attempt has been made here to compute water storage capacity for recharge tanks & filter chambers under different conditions.

Normal Monsoon Rainfall (mm)

Storage capacity/ volume as per roof area (cubic meter)

100 sqm 200 sqm 300 sqm 500 sqm 1000 sqm

600 2.2 4.4 6.6 11.0 22.0 800 2.9 5.8 8.7 14.5 29.0

1000 3.5 7.0 10.5 17.5 35.0 The above computation has been done assuming normal monsoon rainfall, so local variations in rainfall pattern over the last 10-15 years may be taken into consideration. Capacity/ volume recharge tank/ filter chamber may be modified as per local conditions. Storage capacity may also be changed depending upon granularity of aquifer material (fine,

medium, coarse) Permeability of the aquifer should be determined to find the recharge potential of aquifers.

EVERYONE CAN CONTRIBUTE • Leave 10 X 15 feet space as open & unpaved/ lawn, • One can contribute 7000 lt. of rain water to ground water system without any investment. • Similarly, the roadside pavements should remain Kachha for more percolation of rain

water. • This way, huge amount of rain water could be recharged within an urban sprawl, but such

small steps are never initiated.

CHALLENGES & GAPS

The State Govt. has made rain water harvesting mandatory for new housing constructions & Govt. buildings.

But, there are no such rules for existing housing colonies leaving a major chunk of urban areas which remain unutilized for rain water harvesting. This is a big gap.

People’s participation is lacking. No effective monitoring/ implementation mechanism. No department has been made responsible for assessing the impact of RWH, the exact

benefit is yet to be estimated. Result of Piezometers installed in industries is not known. - Area specific concept & the geo-scientific guidelines are not being followed. - RWH schemes are being undertaken everywhere even in non- problematic areas without

considering the local hydrogeological conditions, whereas problematic areas are not being given priority for RWH.

- Various provisions of Government orders on RWH are not being properly implemented. - Hydrogeological parameters are being neglected and the pre-project hydrogeological

surveys in mega schemes are not conducted. - Selection of sites, technology & type of recharge structure is not being done scientifically

as per the hydrogeological considerations. Therefore, desired benefits are not being realized.

- Construction of recharge shafts in ponds has not been stopped, despite risk of contamination.

- Further, in spite of the ban, rain water from paved / unpaved area is allowed in some schemes for direct recharging of aquifers. This is a matter of serious concern because of pollution risk.

- There is no mechanism to monitor the status of rain water harvesting in private buildings of urban areas.

- There are gaps in the implementation methodology. - In urban areas, there is no provision for installing roof top rain water harvesting in existing

colonies/built-up houses. - Maintenance of recharge structure, especially roof top system is being totally ignored. Such

negligence may lead to chocking of structure with pollution risk. - There is also no mechanism by which the real benefit & impact of recharge schemes could

be assessed. - Effective programs & campaign for sensitization /awareness are missing for rain water

harvesting & ground water recharge. - Line departments are implementing recharge schemes in isolation and therefore integrated

micro plans for RWH & GWR in rural and urban areas are yet to be prepared. - Overall, the monitoring & implementation mechanism in the state is almost fragmented.

SOLUTIONS To overcome the various challenges in the execution of rain water harvesting programme in the state of U.P., there are some concrete solutions, which need to be addressed with effective interventions- Separate Institutional mechanism with regulatory framework and adequate & skilled

infrastructure is required to be developed so as to promote, guide, implement, co-ordinate & monitor rain water harvesting and recharging activities.

There should be a ‘State Plan’ for rain water harvesting & ground water recharge with prioritization of separate Micro Plans for problematic areas in urban, rural & industrial segments. These plans & the identified problematic areas should be made public in order to sensitize & create awareness.

Problematic areas should be prioritized in a way that such areas could be fully saturated with complete rain water harvesting & recharge plans/activities in order to achieve cumulative impact on depleting ground water.

Area specific guidelines, technical specifications & standard practices should be strictly followed during the design & implementation stage.

There should be separate strategies/plans for Alluvial & Bundelkhand areas. However, for Bundelkhand- Vindyans, micro watershed approach for rain water harvesting should only be adopted.

To assess the impact of rain water harvesting especially in alluvial aquifers, research (R&D) should be taken-up side by side.

Along with rain water harvesting, Conjunctive Management of surface & ground water resources in both urban & rural areas should be taken up on priority.

In problematic areas, indiscriminate/excessive exploitation of ground water should be discouraged & the roastering system should be enforced. Hence, the conservation & regulation processes should be taken up simultaneously in

problem areas for the ultimate & sustainable management of ground water resource.

NEED TO MANAGE URBAN GROUND WATER

• Separate methodology/norms for Urban Ground Water Assessment should be formulated on priority basis.

• Comprehensive urban ground water management plans with separate regulatory provisions should be prepared.

• Withdrawals from Stressed Aquifers should be strictly regulated & minimized.

• Rain Water Harvesting & Recharging plans should be perceived in totality & not in isolation.

• In Rain Water Harvesting, risk of ground water contamination should never be overlooked

REPLENISHING AQUIFERS – IT TAKES TIME

• It takes long time to replenish depleted aquifers. • Studies show that ground water levels respond slowly to climate changes. • Aquifers can take months or even years to get replenished once pumped for various uses. • Unsaturated soil layer acts as a buffer between the atmosphere & the aquifer. So, where it

rains, it takes time to percolate to the aquifers and less rain may not replenish aquifers. • Studies revealed that it can take months or years for aquifers to recover, depending upon

how deep is the aquifer and how much it has depleted?

EXTENSIVE TRAINING FOR ARCHITECTS/ CIVIL ENGINEERS/ BUILDERS

• Rain Water Harvesting is a technique which requires geo-scientific approach. It is based on scientific aspects, so this technique needs complete understanding of ground water resource.

• To have an update of scientific parameters, technologies, methodologies, guidelines, policy

decisions and design aspects of RWH structures, extensive training programmes on RWH should be organized for the architects, civil engineers, contractors, builders both at government and non government levels, so that they can take up the RWH programme in a scientific way.

Rain Water Harvesting /recharge is neither the only hope and nor the end for rejuvenating the fast depleting resource.

Hence, a thoughtful management process needs to be initiated.