Water Resources Planning and Management

INTRODUCTION

Water is an essential to our existence.

We can survive without food for several weeks, but without
water we would die in a few days.
 WATERSHED

A watershed is simply the geographic area through which water

flows across the land and drains into a common body of water,
whether a stream, river, lake, or ocean.

Or

The area of land drains or shed water into a specific receiving

water body such as lake or river.
 TYPES OF WATERSHED

Watersheds is classified depending upon the size, drainage, shape and land use
pattern.

1. Macro watershed (> 50,000 Hect)

2. Sub-watershed (10,000 to 50,000 Hect)

3. Milli-watershed (1000 to10000 Hect)

4. Micro watershed (100 to 1000 Hect)

5. Mini watershed (1-100 Hect)

 Watershed Management

 Watershed management is meant to capture the sum of the actions

taken to preserve and maintain watersheds.
 Watershed management is a comprehensive package programme to
make all natural resources productive from upper reaches to the
lower reaches of a watershed. If upper reaches of the watersheds
are not properly protected, the lower reaches will be affected.
Gurivajipeta – Prakasam
district
 Cont.’
 The watershed management includes all measures that can protect, manage
and conserve water and other related land resources in a sustainable manner.
 Measures that can be used to protect watersheds include land use controls,
zoning, monitoring, restoration and land use treatment Watershed
management is a process that guide and coordinate the use of land and water
resources in a watershed. When applied locally it will enrich environment
globally.
PRINCIPLES OF WATERSHED MANAGEMENT
The main principles of watershed management are as follows:
 Utilization of land according to its capability.

 Maintenance of adequate vegetative cover on the soil for controlling

soil erosion, particularly during rainy season.
 Conservation of maximum possible rainwater at a place where it falls,
on arable land by contour farming practices.
 Cont.’

 Draining out of excess water from the field with safe velocity to avoid
soil erosion and storing water in reservoirs for future use.
 Prevent erosion in gullies and increase groundwater recharge
through gully plugs at suitable points and intervals.
TYPES OF WATERSHED MANAGEMENT

Grassland development
Gully plugs
Tree plantation
Contour bedding
Land levelling
 HYDROLOGY

The word hydrology is derived from the Greek words, hydro means
Water and logos, which means science. Hydrology is the science of
occurrence, movement and distribution of water above or below the
land surface or in the atmosphere.
 HYDROLOGIC CYCLE
 In order to understand occurrence, circulation and storage of water hydrological
cycle or water cycle can be analysed.
 The precipitation and evaporation continues forever, hence the balance
maintained between the two, which can be understand from water cycle.
 Since it is a continues process it has no starting point, end point or point it
which it pauses.
 Water in ocean vaporizes upward and form clouds which undergo condensation
and forms precipitation that again falls over the ocean predominantly.
Some clouds move over land due to wind and precipitate there
certain portion. This precipitation further undergoes following
1. Evaporation from precipitation
2. Intercepted by obstruction (interception) which may be natural
(plants, trees, mountains) or artificial (structures).
3. Certain portion of interception vaporizes and remaining fall
over the surface.
During photosynthesis plat utilizes water from the soil and transpires certain
portion into the atmosphere.
5. Reaches the surface which further undergoes
a. Evaporation
b. Fill the depression over the ground (depression storage)
c. Flows under gravity from surface into the soil through voids (infiltration).
d. Flows over the surface (surface runoff) and moves to the stream, which
it is termed as stream flow
 If the percolation flows through voids, cracks, fishers of
impermeable strata it is termed as deep percolation.
 Certain portion of the groundwater also meets the stream
over the period of time and termed as base flow or prolonged
interflow.
There are several paths of water cycle each of which has one or
more following aspect
1. Transportation water
2. Temporary storage
3. Change of phase
Transpiration components of water cycle are
Precipitation, Evaporation, Runoff, Transpiration, Infiltration,
Seepage, Percolation
Storage components of water cycle
1. Groundwater storage
2. Soil moisture
3. Storage on surface (lake, ponds, reservoirs)
 GROUNDWATER

 Water contained within cracks, fractures and pore spaces of soil,

sediment and rocks beneath the surface of the earth.
 Study of subsurface flow is equally important since about 30% of the
world’s fresh water resources exist in the form of groundwater.
 Groundwater is a major source of water supply, especially in arid or
semiarid areas where surface water is limited.
 Surface water
 Surface water is any body of water above ground, including streams, rivers,
lakes, wetlands, reservoirs, and creeks.
 The ocean, despite being saltwater, is also considered surface water. Surface
water participates in the hydrologic cycle, or water cycle, which involves the
movement of water to and from the Earth’s surface.
 Precipitation and water runoff feed bodies of surface water.
 Evaporation and seepage of water into the ground, on the other hand, cause
water bodies to lose water. Water that seeps deep into the ground is called
groundwater.
TYPES OF SURFACE WATER
There are three types of surface water.
They are:
 Perennial surface water
 Ephemeral surface water
 Man-made surface water
 Perennial or permanent surface water persists throughout the year
i.e., it contains water at all times. Examples are rivers, swamps, and lakes.

 Ephemeral or semi-permanent refers to bodies of water that are only

present at certain times of the year. Ephemeral surface water includes
small creeks, lagoons, and water holes.

 Man-made surface water is found in artificial structures or infrastructure

designed by humans such as lakes, dams constructed wetlands, and
artificial swamps.
 Forms of subsurface water

Water in the soil mantle is called subsurface water and is considered

in two zones.
1. Saturated zone 2. Aeration zone
Saturated Zone
This zone, also known as groundwater zone, is the space in which all the pores
of the soil are filled with water. The water table forms its upper limit and
marks a free surface, i.e., a surface having atmospheric pressure.

Zone of Aeration
In this zone, the soil pores are only partially filled with water. The space
between the land surface and the water table marks the extent of this zone.
Any flow of water in this zone is in unsaturated soil matrix condition. The zone
of aeration has three subzones.
Soil Water Zone
This lies close to the ground surface in the major root band of
the vegetation from which the water is transported to the
atmosphere by evapotranspiration.

Capillary Fringe
In this subzone, the water is held by capillary action. This
subzone extends from the water table upwards to the limit of
capillary rise.
Intermediate Zone
This subzone lies between the soil water zone and the capillary fringe.
The thickness of the zone of aeration and its constituent subzones
depends upon the soil texture and moisture content and vary from
region to region. The soil moisture in the zone of aeration is of
importance in agricultural practice and irrigation engineering.
 Saturated Formation

The saturated formations are classified into four categories:

1. Aquifer 2. Aquitard, 3. Aquiclude 4. Aquifuge

Aquifer
An aquifer is a saturated formation of earth material which not only stores
water but yields it in sufficient quantity. Thus, an aquifer transmits water
relatively easily due to its high permeability. Unconsolidated deposits of
sand and gravel form good aquifers.
Aquitard
It is a formation through which only seepage is possible and thus the
yield is insignificant compared to an aquifer. It is partly permeable. A
sandy clay unit is an example of aquitard. Through an aquitard
appreciable quantity of water may leak to an aquifer below it.
Aquiclude
It is a geological formation which is essentially impermeable to the
flow of water. It may be considered as closed to water movement even
though it may contain large amounts of water due to its high porosity.
Clay is an example of an aquiclude.
Aquifuge
It is a geological formation which is neither porous nor permeable.
There are no interconnected openings and hence it cannot transmit
water. Massive compact rock without any fractures is an aquifuge.
 HUMAN INFLUENCES IN THE WATER RESOURCES SYSTEM
Our water resources face a host of serious threats, all of which are caused primarily by
human activity. They include sedimentation, pollution, climate change, deforestation,
landscape changes, and urban growth.
One of the most serious threats to water resources is the degradation of ecosystems,
which often takes place through changes to landscapes such as the clearance of
forests, the conversion of natural landscapes to farmland, the growth of cities, the
building of roads, and surface mining.
Each type of change to a landscape will have its own specific impact, usually directly
on natural ecosystems and directly or indirectly on water resources.
 Water Demand
The estimation of demand for water is the key parameter in planning a water
supply scheme. The agriculture sector consumes more than 80 percent of the
total water potential created in our country. The remaining portion is utilized to
meet domestic, industrial, and other demands. The improvement in lifestyle
and associated industrial development of a nation push up the per capita
demand for water
VARIOUS TYPES OF WATER DEMAND
Water demands can be classified into:
1. Domestic Water Demand
2. Industrial Water Demand
3. Institutional and Commercial Water Demand
4. Demand for Public
5. Fire Demand
6. Waste and Theft
Domestic Water Demand
Domestic water demand accounts for 55 to 60% of the total water
consumption. As per IS 1172-1983, the domestic consumption in India
accounts for 135 lpcd (liters/capita/day)

Industrial Water Demand

The per capita consumption of industries is generally taken as 50 lpcd.
Institutional and Commercial Water Demand
On average, a per capita demand of 20 lpcd is required to meet
institutional and commercial water demand. For highly commercialized cities,
this value can be 50 lpcd.
 Public and Civil Use
The per capita consumption for public and civic use can be taken as 10 lpcd.
This water is used for road washing, public parks, sanitation etc.
Fire Demand
Per capita, fire demand is ignored while calculating the total per capita water
requirement of a particular city because most areas have fire hydrants placed
in the water main at 100 to 150 meters apart. The fire demand is generally
taken as 1 lpcd.
Waste and Thefts
This consumption accounts for 55 lpcd. Even if the waterworks are managed with
high proficiency, a loss of 15% of total water consumption is expected.
 INTEGRATED WATER RESOURCES SYSTEM

 The importance of water cannot be stressed enough. There is simply nothing else

like it.

 Water is not only vital for the human population in terms of its consumptive use,

but it is also directly and indirectly related to the livelihood of many in domains

such as agriculture and various industries (as a production input), sewage and

sanitation, and health.

 Life would simply not exist without it, and that is why IWRM is a significant tool.
THE END