Rain water harvesting through cost effective water storage structures in Mid Hills of Himachal Pradesh-

A success story

IP SharmaProfessor and Head

Department of Soil Science and Water ManagementDr YS Parmar University of Horticulture and Forestry,

Nauni-Solan(HP)- 173 230

Agro-climatic zones of Himachal Pradesh

•Himachal Pradesh falls in North-Western Himalayan region having average rainfall of 1200 mm with range of 900-2650 mm per annum.

•The precipitation is mainly through rains and in some districts some of the proportion is through snowfall.

•The 80% of the rains are Monsoonic and confined to July and August and the rest of the rainfall is received during winter months i.e. December to February.

•In rest part of the year, there is always scarcity of water for meeting domestic, agricultural and livestock requirements.

•The problem of water scarcity becomes more acute due to erratic behavior of monsoon/ winter rains i.e. early and late onset and closure of rains and badly affects the sowing of crops and other associated agronomical practices.

To address these problems, the rainwater harvesting and its efficient utilization is one of the steps, which has been taken as a policy in the state and is being demonstrated through low cost technology.

Approach:•The water harvesting in the campus has been undertaken from two natural resources i.e. rainfall and low discharge water springs and rivulets (as low as 1-30L/min).

•Water harvesting can be done by using linear Low Density Polyethylene (LDPE) lined farm pond.

•Before concluding to LDPE lining, a number of other treatments to minimize surface infiltration including treatment of surface soil by sodium salts, bentonite & kaolinite clay minerals.

•For harvesting water using LDPE sheet at the Departmental Research Farm of Soil Science & Water Management, the series of trapezoidal shaped water harvesting farm ponds was constructed in the year 1995-96 using 250 micron black colored LDPE sheet along with lose brick lining having water storage capacity of 4 lacand 1.3 lac liters.

•The harvested water fulfilled the water requirement of differentresearch trials during lean period/water scarcity period, which commonly occur after the receding of monsoons (Sept-December) & after winter rains (March to June).

•This water is being used through micro irrigation system under gravity head only. Realizing the benefits of water storage one more water harvesting pond having storage capacity of 3 lac liters has been constructed in the year 1998 for fulfilling the water requirement of additional research trials being conducted by thePrecision Farming Development Centre.

•Accordingly the water storage capacity through farm ponds has been strengthened by constructing a chain of farm ponds at the university, This technology has been replicated in 560 hectares of land by increasing storage capacity 40 times.•.

•The technology is also being demonstrated at KrishiVigyan Kendra’s and Research Stations of this university.

•The water harvesting structure sites are visited by the progressive farmers/officers of the state as well as from other parts of the country and foreign delegates coming to the university.

•The water storage cost ranges from 0.75 to 1.0 rupee per liter.

Construction procedure

Lining of pond with bricks

LDPE lined water storage pond

Effect of drip irrigation on yield and water savingEffect of drip irrigation on yield and water saving

S. No. S. No. Crop Crop Increase Increase in yieldin yield

(%) (%)

Water Water savingsaving

(%) (%) 1.1. PeaPea 49.4549.45 24.9024.902.2. TomatoTomato 21.6021.60 42.7442.743.3. PeachPeach 58.0058.00 30.0030.004.4. ApricotApricot 23.4023.40 23.3023.305.5. PlumPlum 19.2619.26 26.9026.90

Demonstration of LDPE lined water harvesting pond at farmer’s field

Demonstration of LDPE lined water harvesting pond at farmer’s field

• Keeping in view the success of the LDPE lined farm ponds at the University campus, the Ministry of Water Resources, Govt of India, has sanctioned a project entitled “Farmers Participatory Action Research Progamme” which also aims at demonstration of same technology all over the state at 100 different sites covering dry temperate to subtropical climate having average rainfall of 1000mm to 2650mm including some places where precipitation through snow is only 250mm.

• The same technology is being adopted by different development departments as a part of their developmental programs. Encouraged from the demonstrations of ponds, the farmers have started thinking of replicating the technology with their own efforts and money.

LAYOUT OF TYPICAL PROPOSED LDPE LINED FARM POND

Size : Top 8 × 8 m, Bottom: 3.5 × 3.5 mShape : Trapezoidal Side slope : 1.5:1, Depth 1.5 mThickness of plastic sheet: 250 µTotal capacity : 57.15 m3

Effective capacity : 51.435 m3

CROSS SECTIONAL VIEW AT AA

Depth1.5 m 2.75 m elevationPlastic sheet

0.5m 0.5m

Trench for sheet anchoring Trench for sheet anchoring

0.3 m0.2m

0.5m

Brick lining

0.5m 0.3 m

2.75 m elevation 0.20 m

3.5 m

0.3 m0.3 m

A

Drawing not to scale

3.5×3.5 m10 m

3.5 m

3.5 m

10 m3.5 m 3.5 m 8 m

8 m

8 m

8 m

10m

10 m

A

Silt retention trench 1.5 × 1.5 mThree partitions

FIG. 1. PLAN of PROPOSED LDPE LINED FARM POND

Community based water harvesting(Modern and Traditional)

Water harvesting structure

•The roof top rain water harvesting has also been undertaken in the University campus. Most of the roof top rain water harvesting has been completed by constructing five water storage structures with storage capacity of 1000 m3. •On similar lines, rooftop rain water harvesting in low cost ferro-cement tanks with the financial support of Council for Advancement of People’s Action & Rural Technology (CAPART) is being undertaken in contribution with beneficiaries in terms of cash and kind. •The technology of concrete blocks and ferro-cement tanks is most popular as life span is about 20 years. The water stored in these tanks is being used for kitchen gardening.

• The storage cost of water in concrete block and ferro-cement tanks varies from Rs. 3.5 to 4.5 per liter depending on the condition of the locality.

• About 5000 concrete block and ferro-cement tanks are functioning satisfactorily, providing life saving irrigation to the crops in 200 hectares of land in addition to supplementing the domestic needs of water.

Rooftop rainwater harvesting Ferro-cement tanks/ concrete block tanks