Textbook: Development of Watershed Area - Class 10 PDF Download

Development of Watershed Area

Watershed Area is the area from where the water is collected. It is the area from where the water flows from the higher level to lower level through small streams and nallah. The area where the water is collected ranges from 50 hectares to 500 hectares and more depending on the elevation of land.

The whole farmland of the village is not flat. Many types of hilly lands are found in the village such as hillslope lands, ditches, flat lands . In short, water of this particular area which naturally flows from the mountains through small streams and flows through a nallah the whole area is called 'Watershed Area'.

In order to implement the watershed area development plan, the small watershed area has to be considered as a first priority . The watershed area has to be selected according to the geographical location of the land.

In the selected watershed area, various treatments are required to stop the erosion of the ridge to the soil from the top to valley and to stop the flow of water.

Various groundwater conservation works have to be carried out on all the lands in the watershed area to block and redeem water according to the elevation.

Watershed Area Development Program

• Rainfall and climate in watershed area.
• Size, slope and structure of watershed area.
• Network of rivers- streams, type and its proportion.
• Type of land- light, medium, heavy land.
• Thickness of different soil layers found after digging of land.
• Geological conditions, types of rocks, decomposition, cracks and joints in it.
• Availability of spreading of groundwater.
• Rate of water seeps into the soil.
• Properties and scope of water retaining rocks.
• Types of surrounding trees and shrubs, grass and shrubs cover on the ground, types of forests.
• Information on how and to what extent land is used and methods of land use.

Survey of Watershed Area

• In order to carry out development work of watershed area, it is necessary to first survey the entire area.
• From this survey we can get information about the ups and downs of the land, the direction of water flow, the type of land, how much water can be blocked from the drain etc.
• Based on this information, we get to know what kind of work is to be done in the watershed area and to what extent is to be done.
• The work has to start from the highest point in the area selected for treatment in the watershe.
• As a result, rainwater from the hills gradually begins to seep into the lower region. Groundwater level rises in the first year and the water level in the wells below it rises.
• Thus the area under horticulture increases and agricultural production also increases.

Treatment Methods for the Development of Watershed Area

a) Continuous Contour Trenches - CCT

The land at the top of the hill have high slope. The rain water that falls on it is carried away by the force. Therefore, as the soil

Continuous Contour Trenches in Hill Slope

• Soil Erosion Control: The soil that flows with the water stays in the trenches, preventing soil erosion.
• Water Infiltration: Rainwater falling on the ground seeps into the soil across all parts of the field due to the digging of contour trenches.
• Water Accumulation: Rainwater flows for a maximum of 5-6 meters, accumulates in the trenches, and seeps into the soil.

B) Loose Boulder Structure

Initial Step

• Small streams formed by rainwater running down the slopes need to be blocked.
• A causeway of stones should be laid to block the water flowing through these streams.

Causeway Construction

• Small stone causeways should be laid one below the other according to the slope.
• The distance between causeways should be such that the foundation level of the causeway above the stream and the head of the causeway below it are equal.
• The height of these causeways should be kept up to 2 meters, depending on the slope of the land.

Grass and Shrub Planting

• Apply khas grass or other grass on the soil compacted on the embankment or causeway.
• Plant small shrubs, such as berry, herbal tea, marigold, and basil, at a distance of half a meter on the lower side of the dam or causeway.
• These plants will strengthen the dam or causeway and help block water effectively.

Nala Bunding

Nala Bunding is a technique used to block the flow of rainwater from the nala (drainage channel) to store water. It involves the construction of earthen or cement causeways to create a barrier.

Key Points:

• Earthen Causeways/Dams: Can be built with a maximum height of 4 meters.
• Base Preparation: The base should be dug properly, and black soil should be filled at the bottom to prevent water seepage.
• Flood Prevention: When constructing multiple causeways/dams in a nala, ensure that floodwater from the lower nala does not reach the upper nala.
• Water Level: Increases the water level in the well below the causeway/dam as water seeps into the soil.
• Crop Irrigation: Stored water in the nala can be used for irrigation.
• High Water Flow: In areas with high and fast water flow, use cement and stone instead of soil for construction.
• Modern Construction: RCC (Reinforced Cement Concrete) and ferrocement are now commonly used for building causeways/dams.

Nala Bunding with Cement Stones

Guidelines:

• Watershed Area: Should be between 40 hectares to 500 hectares.
• Slope: The slope of the bottom of the nala should be less than 3%.
• Width: The width of the bottom of the nala should be less than 30 meters.

Vanarai Check Dam

Construction Process:

• Material Preparation: Fill empty cement bags with a mixture of soil and sand. Sew the mouths of the bags with plastic thread.
• Bag Placement: Place the filled bags side by side to form the first layer. When adding the second layer, offset the bags to cover the joints of the first layer.
• Soil Layer: After 2-3 layers of bags, add a layer of soil to close fine cracks and strengthen the dam.

Benefits:

• Cost-Effective: This method is simple and low-cost.
• Horticulture Expansion: Increases horticulture area by diverting water from the nala.

Gabion Check Dam

When to Use:

• High Slope Areas: Where rainwater flows quickly due to steep slopes.
• Inadequate Soil: Where earthen dams cannot withstand the water flow.
• Limited Resources: Where concrete bases are not available.

Construction Method:

• Coarse Stone Mesh: Create a horizontal dam using coarse stone mesh.
• Binding: Tie stones and nets together and place them horizontally in the nala.
• Natural Materials: Add small tree branches, grass, and mulch around the dam to enhance its effectiveness.

Gabion Dam

• A Gabion Dam is a structure built across a river or stream using wire mesh baskets (gabions) filled with stones.
• The purpose of this dam is to hold back water, creating a reservoir that can be used for various purposes such as irrigation, drinking water supply, and flood control.
• The wire mesh baskets are usually made of galvanized steel to prevent rusting and ensure durability.
• The stones used to fill the baskets are typically sourced locally and can vary in size, but they should be large enough to prevent washing away during heavy rains.
• Gabion Dams are particularly useful in areas where traditional dam construction methods are not feasible due to the lack of concrete or other materials.
• They are also environmentally friendly as they use natural materials and have a lower carbon footprint compared to concrete dams.

Loop Bunding

Loop bunding is a technique used to create a loop or bund around a water source, usually in hilly or uneven terrain. This method involves the following steps:

1. Selection of Site: Choose a location where water naturally flows and collects, such as a nala (stream) with a flow rate of at least 150 liters per second. The bottom of the nala should preferably be open rock to facilitate water flow.
2. Construction of Bund: Build a stone wall or bund on the lower side of the selected site, with a thickness of 0.60 meters. The bund should extend 2 meters inside both sides of the nala to create a loop.
3. Digging of Banks: Excavate both banks of the nala to divert the collected water into the fields. This diverted water will be used for irrigation of nearby crops.
4. Temporary Dams: As the water level rises in the nala, temporary dams can be constructed to further divert the water to adjacent fields.
5. Spread of Water: Ensure that the diverted water spreads evenly in the fields, ideally 50 to 100 meters away from the dam.

Loop bunding is an effective method for water conservation and irrigation in areas with limited water resources. It helps in storing and utilizing water efficiently, especially in regions with seasonal rainfall.

Innovation in Water Conservation

• Bhanjibhai Mathukiya from Saurashtra developed a semicircular dam to conserve water from streams and nalas, addressing local water shortages.
• The dam consists of arched structures built in succession, inspired by the vertical arch design of a British-era railway bridge.
• Constructed quickly in four days using stone and riverine sand at a cost of ten thousand rupees .
• Recognized for his innovation, Bhanjibhai Mathukiya received an award from the National Innovation Foundation by the President of India.
• Semicircular dams based on this concept have been implemented in Shirpur taluka of Dhule district, Maharashtra, and at Botadwadi , Hantur in Sangli district.

Farm Pond

• Instead of removing excess water from fields, farmers should consider digging and storing farm ponds to manage this water.
• A typical farm pond pit should measure 30 meters long, 20 meters wide, and 3 meters deep , with the sides and bottom properly sealed and sloped.
• In saline areas, such as the Konkan coast , the pond's depth should be around 2 meters .
• Such ponds can store approximately 1500 cubic meters of water , which can be used for agricultural purposes.
• The government has a scheme for 'farm pond on demand' to encourage this practice.

Importance of Timely Sowing

• Timely sowing after the first rains is crucial for increasing crop yield.
• Sowing should be done evenly after horizontal tillage on slopes to retain soil moisture, potentially increasing yields by 1.5 times.

Techniques for Water Management and Soil Conservation

1. Horizontal Tillage on Slopes

• Plowing land on slopes horizontally helps create small causeways that allow rainwater to seep into the soil , reducing erosion.
• This method is particularly effective for rainwater that falls in May, as it enhances soil convenience for cultivation.

2. Strip Sowing

• Sowing crops in strips on the slope of the land helps reduce soil erosion and facilitates rainwater absorption in the same area.
• Alternating strips of tall crops like sorghum and millet with shorter crops like groundnut and pulses enhances moisture retention in the soil.
• For example, plowing every 5 to 6 meters at the same level and sowing tur and groundnuts in strips helps rainwater seep into the soil without being carried away.

3. Dryland Orchard Planting Techniques for Water Saving

1. Planted at Root Place: In this method, the seed of the fruit tree is sown directly in a pit without using grafted trees. The pit is filled with a mixture of manure, organic matter, and soil, allowing the seed to root throughout the year. Once the seedling develops, grafting is done at the same spot. This technique encourages deep root growth and reduces excess water consumption.
2. Watering Directly Near the Roots: This recent method involves placing a vertical pot with a small hole or a half-buried plastic bottle near the tree trunk, allowing water to seep directly into the roots. Another technique involves using buried PVC pipes filled with vermi compost and sand, creating sand columns that direct water to the roots, retaining moisture for a longer period. This approach is part of Climate Resilient Agriculture (CRA).

4. Water Crisis Mitigation Measures

To address the worsening water crisis in various parts of the country, it is essential to implement permanent measures and remedies.

Remedial plan for water problem

1. Water conservation area

• Water conservation through watershed development is considered a long-term solution for drought conditions.
• Implementing policies for well restructuring, river deepening and widening, and dam construction can help solve the water problem permanently.
• Techniques like 'Block water and Seep water' can effectively utilize every drop of rain and address the water shortage issue.

2. Groundwater recharge

• Groundwater levels are declining rapidly in both urban and rural areas due to excessive extraction for domestic, agricultural, and industrial use.
• Initiatives to recharge artesian wells and regular wells are necessary to increase groundwater levels and promote proper rainwater usage.
• Groundwater recharge not only raises the groundwater level but also facilitates the efficient use of rainwater.

3. Restrictions for water pollution

• Citizens should avoid performing rituals in rivers, streams, wells, canals, and other water sources.
• Factory waste, hazardous chemicals, and sewage should be disposed of in an environmentally friendly manner, and polluted water should be treated and recycled.

Internet my friend

Find out more information about the following activities on the Internet.

1. Ralegansiddhi experiment- Vibhushan Anna Hajare
2. Vanrai experiment- Padma Vibhushan Mohan Dharia
3. Water Conservation Experiment- Padma Vibhushan Sri Sri Ravi Shankar
4. Hiware Bazar- Padmashree Popatrao Pawar
5. Water community experiment- Hon. Rajendra Singh Rana
6. Shirpur Pattern- Khanapurkar Shri. Suresh
7. Jal Dindi Movement- Dr. Yevle
8. Nisargabet experiment- Dr. Upendra Dhonde
9. Nidhal village Development- Chandrakant Dalvi
10. Jalasamvad- Dr. Datta Deshkar

Exercise

1. Why is it necessary to implement watershed development program?
2. Write information about the activities implemented for watershed development in your area.
3. What remedial methods are involved in watershed area development?
4. How to recharge groundwater in urban areas? Explain with an example.
5. How can the technique of 'block water, seep water' be made successful while cultivating the land? Explain with an example.

Introduction

The watershed development programme is being implemented in the villages of Chaul, Tumb, and Karanjwadi in the Raigad district of Maharashtra.