Collection and Conveyance of Water

Collection & Conveyance of Water

Unit-II

BTCI05006/ MBCI05006

Collection & Conveyance of Water

Unit-II

Syllabus• Collection and conveyance of water: Types of intake structure, design

of intake structure, estimation of fluid flows, engineeringrequirements of conduits with respect to their performance, types ofconveyance system, hydraulic design of conveyance conduits, variousmaterials of pipes, appurtenances, and issues associated withconveyance of water.

• Pumps for lifting of water: Types of pumps, selection of pumps,design of pumping main for conveyance of water, economicaldiameter of pumping main, pumping station

Intake Structures

Introduction• In any water supply project the first step is to select

the source of water from which water is drawn. Thedevice Installed for the purpose of drawing waterfrom the source of water are called Intakes

Intake Structures

Intake Structure• The basic function of intake structure is to help in safely withdrawing

water from the source and then to discharge this water in to thewithdrawal conduit, through which it reaches the water treatmentplant.

• It is constructed at the entrance of the withdrawal conduit and therebyprotecting it from being damaged/clogged by ice,debris.

• Some times from reservoirs where gravity flow is possible, water isdirectly transmitted to the treatment through intake structure.

• If gravity flow is not possible, water entering intake structure is lifted bypumps and taken to the treatment plant.

Intake Structure

Selecting Location Of Intake Structure• Site should be near the treatment plant to reduce conveyance cost.• Intake must be located in the purer zone of the source so that best quality

water is withdrawn from source to reduce the load on the treatment plant.• Intake must never be located in the vicinity of waste water disposal point.• Intake must never be located near the navigation channels so as to reduce

chances of pollution due to waste discharge from ships.• The site should be such as to permit greater withdrawal of water, if

required in future.

Selecting Location Of Intake Structure

• Intake must be located at a place from where it can draw water evenduring the driest period of the year.

• The intake site should remain easily accessible during floods andshould not get flooded.

• In meandering rivers, the intakes should not be located on curves oratleast on sharp curves.


Types of IntakesAccording to type of source• River Intake• Canal Intake• Reservoir Intake• Lake IntakeAccording to position of Intake• Submerged Intake • Exposed IntakeAccording to presence of water in the tower• Wet Intake• Dry Intake

Intakes for Collecting Surface Water

Intakes for Collecting Surface WaterAccording to position of Intake• (a) Submerged Intake• (b) Exposed Intake• The submerged Intake structures are those which are constructed entirely

under water. They are less expensive to construct but are difficult tomaintain. Such intakes are commonly used to obtain water from lakes

• The Exposed intakes is in the form of well or tower constructed near thebank of river or in some cases even away from the bank of river. They aremore common due to ease in operation and maintenance

Intakes for Collecting Surface WaterAccording to presence of Water in the towerWet IntakeDry IntakeA Wet intake is that type of the Intake tower in which the water level ispractically the same as the water level of the source of supply. SuchIntakes are also called as Jack Well and is most commonly UsedIn Dry Intake There is no water in the intake tower. Water entersthrough entry port directly in to conveyance pipes. The dry Intaketower is simply used for the operation of valves.

Simple Lake Submerged Intakes• It consists of a simple concrete block or a rock filled timber crib

supporting the starting end of the withdrawal pipe.• The intake opening is generally covered by screen so as to prevent the

entry of debris, ice etc.. in to the withdrawal conduit.• In lakes, where silt tends to settle down , the intake opening is generally

kept at about 2 to 2.5m above the lake bed level to avoid entry of silt.• They are cheap & do not obstruct navigation• They are widely used for small water supply projects drawing water from

streams or lakes having a little change in water level through out year.• Limitation is that they are not easily accessible for cleaning & repairing.

Simple Submerged Intakes

Rock Filled Timber Crib -Submerged Intake

Intakes for Collecting Surface WaterRiver Intake

A River Intake is located on the upstream side of the city to getcomparatively better quality of water. They are either locatedsufficiently inside the river so that necessary demand of watercan be met in all the seasons of the year.

The intake tower permits the entry of water through several entryports located at various levels to cope with fluctuations in the waterlevels during different seasons.

This are also called as penstocks. The penstocks are covered withsuitable design screens to prevent entry of floating impurities.

Intake Towers

• They are widely used on large water supply projects drawing water from riversor reservoirs having large change in water level.

• Gate controlled openings called Ports are provided at various levels in theseconcrete towers to regulate the flow.

• If the entry ports are submerged at all levels, there is no problem of anyclogging or damage by ice or debris etc..

• There are two major types of intake towers:(a) Wet intake towers(b) Dry intake towers

Wet Intake Towers

• It consist of a concrete circular shell filled with water up to the reservoirlevel and has a vertical inside shaft which is connected to thewithdrawal pipe.

• The withdrawal pipe may lie over the bed of the rivers or may be in theform of tunnels below the river bed.

• Openings are made in to the outer concrete shell as well as, in to theinside shaft.

• Gates are usually placed on the shaft, so as to control the flow of waterin to the shaft and the withdrawal conduit.

• The water coming out of the withdrawal pipe may be taken to pumphouse for lift (if treatment plant is at high elevation) or may be directlytaken to treatment plant (at lower elevation).

Wet Intake Towers

Dry Intake Towers• The water is directly drawn in to the withdrawal conduit through the

gated entry ports.• It has no water inside the tower if its gates are closed.• When the entry ports are closed, a dry intake tower will be subjected

to additional buoyant forces.• Hence it must be of heavier construction than wet intake tower.• They are useful since water can be withdrawn from any selected level

of the reservoir by opening the port at that level.

Dry Intake Towers

Intake

Intake

• There are two types of intakes as under• (i) Dry Intake Tower• In dry intake tower the entry ports are directly connected with the

withdrawal conduit and water inside the tower when gates are in aclosed position. Dry Intake tower has a merit that the intake towerbeing dry is made accessible for inspection and operation besidesthat the water can be withdrawn from any level by opening the portat that level.

• However, dry intake tower is massive in structure, than wet intake towithstand additional buoyant forces to which it is subjected when theport gates are closed.

Dry Intake Tower

Intake

Wet Intake Tower• A wet intake tower has entry ports at various levels and the vertical

shaft is filled with water up to reservoir level. It differs from the dryintake tower is that the water enters from the ports into the towerand then into the withdrawal conduict through separate gatedopenings. As such it consists of a circular shell made of concretefilled with water up to reservoir level, housing another inside shaftdirectly connected to the withdrawal conduit. It is less costly toconstruct and is usually not subjected to flotation and certain otherstress may not be the consideration.

Wet Intake Tower

Trash Racks• Trash rack is defined as a screen or grating provided at the entrance

of intake to prevent entry of debris. Trash racks usually consists oftrash sections 1.5 to 2 m wide and not too long for handling, madeup of mild steel flats on edge 5 to 15 cm. Coarse trash racks areprovided near the ports to prevent large drift, such as cakes of ice,roots, trees and timber from being drawn into the intake.

Trash Racks• In some part of the intake fine trash racks are provided to protect the

machine & machine parts through which water flows. In cold region,trash racks is often clogged with fragile ice. Electrical heating forsmall trash racks are provided to prevent ice formation on the racks.

• The floating debris accumulated, as are denied entry into the intake,are removed with the help of power driven rack-rakes.

Trash Racks

River Intake Structures

• They are generally constructed for withdrawing water fromalmost all rivers.

• They can be classified in to two types(1) Twin well type of intake structure(2) Single well type of intake structure

Twin Well Type Intakes

• They are constructed on almost all types of rivers, where the river water hugsthe river bank.

• A typical river intake structure consists of 3 components:(a) An inlet well(b) An inlet pipe (intake pipe)(c) A jack well

• Inlet well is usually circular in c/s, made of masonry or concrete.• Inlet pipe connects inlet well with jack well. It has a min dia of 45cm, laid at

slope of 1 in 200. Flow velocity through it<1.2m/s• Water entering jack well is lifted by pumps & fed into the rising main• Jack well should be founded on hard strata having B.C> 450 kN/m2.

Twin Well Type Intakes

Single Well Type Intakes• No inlet well & inlet pipe in this type of river intake.• Opening or ports fitted with bar screens are provided in the jack

well itself.• The sediment entering will usually be less, since clearer water will

enter the off-take channel.• The silt entering the jack well will partly settle down in the bottom

silt zone of jack well or may be lifted up with the pumped watersince pumps can easily lift sedimented water.

• The jack well can be periodically cleaned manually, by stopping thewater entry in to the well.

Single Well Type Intakes

Canal Intakes

Canal Intakes• In case of a small town a nearby Irrigation Canal can be used as

the source of water. The Intake Well is generally located in the bankof the Canal. Since water level is more or less constant there is noneed of providing inlets at different depth. It essentially consist ofconcrete or masonry intake chamber or well.

• Since the flow area in the canal is obstructed by the constructionof Intake well, the flow velocity in the canal decreases. So thecanal should be lined on the Upstream & Downstream side of theintake to prevent erosion of sides and bed of channel

Intakes For Sluice Ways Of Dams

Intakes for Reservoirs

• When the flow in the river is not guaranteed throughout the year,a dam is constructed across the river to store the water in thereservoir so formed.

• Reservoir Intakes essentially consists of an Intake towerconstructed on the slope of Dam at such a place where Intake candraw water in sufficient quantity even in the driest period. Intakepipes are fixed at different levels, so as to draw water near the surfacein all variations of water levels.

An intake structure constructed at the entrance of conduitand thereby helping in protecting the conduit from beingdamaged or clogged by ice , trash, debris, etc.., can vary from asimple Concrete block supporting the end of the conduit pipeto huge concrete towers housing intake gates, Screens, pumps,etc.. and even sometimes, living quarters and shops foroperating personnel.

Lake Intake• Lake Intake are mostly submerged intake. These Intakes are

constructed in the bed of lake below the low water level so as to drawwater even in dry season. It mainly consist of a pipe laid in the bed ofthe lake. One end of the pipe which is in middle of the lake is fittedwith bell mouth opening covered with a mesh and protected timberor concrete crib. The water enters in the pipe through the bell mouthopening and flows under gravity to the bank where it is collected in asump well and then pumped to the treatment plant for necessarytreatment.

Submerged Intake

Advantages Intakes• No Obstruction to navigation• No danger of floating bodies• No ice trouble

Intake

Intake

• The general requirement of an Intake Structure are:

Structural Stability

• The Intake structure is stable to resist water and wave thrust besideswind pressure when reservoir is empty as also against the shock ofearthquakes.

Hydraulic efficiency

• There is smooth entry into the water conductor system to ensuregradual transformation of static head to conduct velocity so as toinvolve hydraulic losses.

Intake

Intake

Velocity Limitation

• The velocity through trash rack gates and ports is within economic andsafe limits.

Operational efficiency

• The intake and the equipments are such as to prevent/ minimize ice,floating trash and coarse sediment entering the water conductor systemto ensure good operational efficiency.

Intake

• The main components of an irrigation intake structure are

(i) Trash rack and supporting structure

(ii) Bell mouth entrance with transition and rectangular circularopening, and

(iii) Gate slot closing devices with air vents.

Trash Rack

Bell Mouth Entrance

Gate slot closing devices with air vents.

Intake

Function of Intakes

• Intake structure serve to permit withdrawal of water in thereservoir over a predetermined range of reservoir levels to the outlet.

• The other functions served by an intake are to support necessaryauxiliary appurtenances such as trashrack, fish screens andbypass devices, etc.,.

Intake

Intakes

Intake

Intake

Run-of-River Intakes

• In a run-of-River plants, intake is apparent to power house anddraws water from the river without any appreciable storageupstream of the diversion structure. Characteristics of river flows.,the intake is designed to withstand high peaks and short duration floodflows and high sediment loads. The bell mouth entrance isessentially provided with trash racks.

Run-of-River type Intake

Intake

Canal Intake

• It is also a variant of the run-of-river intake, that is providedadjacent to the diversion weir/ barrages to admit water into thecanal. It is designed to function under low heads and the topographyand geology permits straight reach suitable for it. Sedimentexcluder is an essential component of the intake. The crest of theintake is generally raised to prevent entry of coarse fraction of bedload into the canal.

Canal Intake

Intake

Reservoir Type Intakes

• Intake tower classified as Submerged, dry and wet intakes fall inthis category.

(i) Submerged Intake

• An Intake Structure which remains entirely under water duringits operation is termed as submerged intake. It is provided wherethe structure serves only as an entrance to the outlet conduct andwhere ordinarily cleaning of the trash is not required. The conductintake may be inclined, vertical or horizontal in accordingly withthe intake requirements. . An Inclined Intake may be providedwith gates and operated on the upstream slopes of a low dam.

Submerged Intakes

Submerged Intake

Intake

Intake tower

• An Intake tower is used to draw water from the reservoirin which there are huge fluctuations in water level orquality water is to be drawn at the desirable depth or both. ItConsist of an elaborate exposed or tower like structurerising above maximum reservoir level and closely locatedto the dam body or the bank of the stream so as to beapproached by a connecting bridge of minimum span.

Intake

Intake

• The Intake tower consist of circular concrete structureprovided with openings or ports for water entry fittedwith trash racks to prevent the entry of debris and ice largeenough to injure the equipment and gates that control theflow through intakes into the feeding conduct outlet.

• It has a merit that best quality of water available atdifferent depths at different seasons of the year can bedrawn through port openings at different elevations.

Design of Intake• An Intake should be designed and constructed on the basis of following

points• Sufficient factor of safety should be taken so that intake work can resist

external forces caused by heavy waves and currents, Impact of floatingand submerged bodies, ice pressure etc..

• Intake should have sufficient self weight, so that it may not float by the uptrust of water and washed away by the current

• If Intake work is constructed in navigation channels, it should be protectedagainst the impact of the moving ships by cluster of pile around

• The foundation of Intake should be taken sufficient deep so that they maynot be undermined and current may not overturn the structure.

Design of Intake• To avoid the entrance of large and medium objects and fishes screens

should be provided on the Inlet, sides• The Inlet should be of sufficient size and should allow required

quantity of water.• The positions of Inlet should be such that they can admit water in all

seasons near the surface where quality of water is good.• Number of Inlets should be more so that if any one is blocked, the

water can be drawn from others. The inlets should be completelysubmerged so that air may not enter the suction pipe.

Canal Intake

Design procedure for IntakesCanal Intake• If Population is given and rate of water Supply is given the discharge

required by the city/town can be found• Q= Population x Rate of SupplyDesign of Coarse Screen• Generally the coarse screens are made of vertical bars of 15 to 20

mm dia and are spaced at 20 to 50 mm Centre to Centre• Velocity through the screens is assumed to be around 0.15 m/sec

Canal Intake

Design procedure for Intakes• Area of Screens= Discharge

Velocity through screensQ= A x VHeight of the screen is found assuming that the bottom of the screen iskept 0.15 m above canal bed and also considering the minimum waterlevel in the canal.After finding height, length of the screen opening can be found out.Length of screen = Area

Height

Canal Intake

Design procedure for Intakes• Number of bars required can be found after assuming the diameter

and spacing of the bars.• Total length of screen will be length of opening + length occupied by

bars.Design of bell mouth entry• To find the area of bell mouth entry first assume the velocity through

bell mouth generally around 0.3 to 0.35 m/sec. After getting the areafind the dia of bell mouth

Canal Intake

Design Procedure for IntakesDesign of Intake Conduit• Assume the velocity of flow through conduit, generally 1.0 to 1.5

m/sec• Find , A= Q

VThen Using Hazen William formula, find the head loss and the sloperequired, Charts can be used.

River Intake• First Design the Intake Well. Dia is generally between 4 to 7.5 m.

Using discharge find the area and the diameter.• If rectangular find length and width after finding the length and

width of the screen required.• Design procedure for coarse screen and outlet conduct is almost

same as canal Intake.

Example• Design a bell mouth canal intake for a city of 70,000

persons drawing water from a canal which runs only for 10hrs. a day with a depth of 1.6 m. Also calculate the head lossin the intake conduit if the treatment plant is 0.5 km away.Assume average consumption per person= 160 l/d. Assumethe velocity through the screens and bell mouth to be 0.15m/s and 0.3 m/s respectively.

Example• Discharge required by the city= 70000 x 160 (Population x rate of supply)= 11,200,00011.2 MLD (Million litre per day)Since the canal only runs for 10 hrs. a day, this whole dailyflow is required to be drain in 10 hrs.

ExampleTherefore the Intake load= 11.2 = 1.12 ML/Hour

10= 1.12 x 10 6 m3 / hr....

10 3

1.12 x 10 3 m3 /sec60 x 60

= 0.311 m3 /sec

ExampleDesign of Coarse Screen• Area of Coarse Screen = Discharge

Velocity through the screenVelocity through the screen = 0.15 m /secArea of the coarse screen = 0.311 = 2.075 m 2

0.15Assume the minimum water level is 0.3 m below the normal water level. Thebottom of the screen is kept at 0.15 m above the bed level. The top of screen is keptat minimum levelTherefore available height= 1.6 – 0.3- 0.15

= 1.15 mMinimum length of the screen= 2.075 = 1.80 m

1.15

Canal Intake

ExampleAssume the clear opening between vertical bars to be 30 mm each we have• Number of opening = 1.8 = 60

0.03Therefore no of bars= 59

Assume the dia of bar as 20 mmLength occupied by the bar of 20 mm = 59 x 0.02= 1.18 mTherefore length of screen= 1.8 + 1.18= 2.98Say 3 mHence provide coarse screen of length 3.0 m and height 1.15 in rectangular intakewell

Canal Intake

ExampleDesign of Bell Mouth Entry• Area of Bell mouth entry = Discharge

Velocity through the bell mouth= 0.311

0.3= 1.037 m 2

Diameter d of the bell mouth entry as= ∏ d 2 = 1.037

4

Example• D={ 4 x 1.037} 1/2

∏

= 1.15 mIf the dia of small holes in the screen is assumed to be 15 mm (10 to 20mm).Then area of each hole= ∏ x (0.015) 2

4= 1.767 x 10 -4

Therefore number of holes on the bell mouth = Area of bell mouthArea of one hole

= 1.0371.767 x 10 -4

= 5868.2Say 5869

Canal Intake

ExampleDesign of Intake Conduit• Assume Velocity of flow in the conduit as 1.5 m/sec• Area of conduit required = Discharge

Velocity= 0.311 = 0.2073 m 2

1.5Dia of pipe D will be∏ D2 = 0.20734= 0.514Say 0.55 m

Canal Intake

Example• Flow velocity through this 0.55 m dia conduit will be= V = Q = 0.311 = 1.31 m /sec

A= x (0.55) 2

4

assume velocity of 1.5 m /sec

∏

Example• Head loss through the conduit up-to treatment plant is calculated by using

Hazen William’s eq n

• V= 0.85 CH R 0.23 S 0.54

• Where ,• CH= Coefficient of the Pipe• = 130 for Cast Iron Pipe• R= Hydraulic mean depth• = d/4 ( for pipe running full)• = 0.55 = 0.138 m

4V= VelocityS= Slope

Example• Therefore,• 1.5 = 0.85 x 130 x (0.138 ) 0.63 S 0.64

• S 0.54 = 1500.85 x 130 x (0.138) 0.63

= 0.047S= (0.047) 1 /0.54

= 3.51 x 10 -3Or 1 in 284.73S= HL = Head Loss

L Length of PipeLength of pipe is equal to the distance of Intake from treatment plants 0.5 km =500 mHL= 3.51 x 10 -3 x 500= 1.755 m

Example• Design a bell mouth canal Intake for a City of 1,00,000 persons

drawing water from a canal which runs for 10 hrs.. a day with adepth of 2 m. Also calculate the head loss in the intake conduit if thetreatment works are 1 km away. Draw a neat sketch of canal Intake.Assume average consumption per person= 150 l/day. Assume thevelocity through the screens and bell mouth to be less than 15 cm/secand 35 cm/sec

Canal Intake

ExampleDischarge through IntakeDaily Discharge= 150 x 1,00,000= 15,000,000 l/day• Since the canal runs only for 10 hrs. per day.• Intake Load/hr = 15,000,000 = 15,000,00 lit/hr

10= 15,00 m3 /hr....Q= 1500 = 0.4166 m3 /sec

60 x 60

ExampleArea of Coarse Screen I front of Intake• Area of Screen= 0.4166= 2.777 m 2

0.15Let the area occupied by solid bars by 30 % of the total areaTherefore the actual area= 3.96 m 2Let us assume minimum water level at 0.3 m below normal water level. Also let us keep bottom of the screen at 0.15 m above canal bed and top of screen at the minimum water level.Available height of screen= 2- 0.3-0.15 = 1.55 mRequired length of screen= 3.96 = 2.55 m

1.55Hence provide a length of 2.6 mHence provide a screen of 1.55 x 2.6 m

ExampleDesign of Bell Mouth Entry• Area of Bell mouth Ab= 0.4166 = 1.301 m 2

0.32Dia db= { 1.301 x 4}1/2 = 1.65 m

3.14Hence provide a bell mouth of 1.7 m dia

ExampleDesign of Intake Conduit• Let us assume a velocity of 1.5 m/sec in the conduit• Dia of conduit D ={ 0.4166 x 4 } 1/2 = 0.35 m

1.5 x 3.14However, provide 0.5 m dia, conduit, so that actual velocity of flow isV = 0.4166 x 4 = 2.12 m/sec

3.14 x (0.5) 2

ExampleFor head loss through the conduit• V= 0.849 C R 0.63 S 0.54

• C= 130• R= D/4 = 0.5 /4 = 0.125• Hence Slope S of the energy line,• 2.12 = 0.849 (130) (0.125) 0.63 S 0.54

• S= 7.533 x 10 -3

• S= HL/L• HL= S x L= 7.53 m

Canal Intake

Conveyance of Water• Water is drawn from the sources by Intakes. After it’s drawing the

next problem is to carry it to the treatment plant which is locatedusually within city limits. Therefore after collection, the water isconveyed to the city by mean of conduits. If the source is at higherelevation than the treatment plant, the water can flow undergravitational force.

• For the conveyance of water at such places we can use open channel,aqueduct or pipe line, Mostly it has been seen that the water level inthe source is at lower elevation than the treatment plant, In such casewater can be conveyed by means of closed pipes under pressure

Conveyance of Water

Conveyance of Water• If the source of supply is underground water, usually there

is no problem as, these sources are mostly in theunderground of the city itself. The water is drawn from theunderground sources by means of tube-wells and pumpedto the over-head reservoirs, from where it is distributed tothe town under gravitational force. Hence at such placesthere is no problem of conveyance of water from sources tothe treatment works.

Conveyance of Water

Conveyance of Water• In case of sources of water supply is river or reservoir

and the town is situated at higher level, the water willhave to be pumped and conveyed through pressurepipes. If the source is available at higher level thanthe town, it is better to construct the treatment plantnear the source and supply the water to the townunder gravitational forces only,

Conveyance of Water

Conveyance of WaterOpen Channels• These ae occasionally used to convey the water from the source to the

treatment plant. These can be easily and cheaply constructed bycutting in high grounds and banking in low grounds.

• The channels should be lined properly to prevent the seepage andcontamination of water. As water flows only due to gravitationalforces, a uniform longitudinal slope is given. The hydraulic gradientline in channels should not exceed the permissible limit otherwisescouring will start at the bed and water will become dirty. In channelflow there is always loss of water by seepage and evaporation,

Open Channels

Conveyance of WaterAqueducts• Aqueducts is the name given to the closed conduit constructed with

masonry and used for conveying water from source to the treatmentplant or point of distribution. Aqueduct may be constructed withbricks, stones or reinforced cement concrete. In olden daysrectangular aqueduct were used, but now a days horse-shoe orcircular section are used. These aqueduct are mostly constructedwith cement concrete The average velocity should be 1 m/sec

Aqueducts

Conveyance of WaterTunnels• This is also a gravity conduit, in which water flows under

gravitational forces. But sometimes water flows under pressure andin such cases these are called pressure tunnels. Grade tunnels aremostly constructed in horse-shoe cross-section, but pressure tunnelhave circular cross-section. In pressure tunnels the depth of water isgenerally such that the weight of overlying material will be sufficientto check the bursting pressure. Tunnels should be water tight andthere should be no loss of water.

Tunnels

Conveyance of WaterFlumes• These are open Channels supported above the ground over

trestles etc.. Flumes are usually used for conveying wateracross valleys and minor low lying areas or over drains andother obstruction coming in the way. Flumes may beconstructed with R.C.C, wood or metal. The common sectionare rectangular and circular.

Flumes

Conveyance of WaterPipes• These are circular conduits, in which water flows under pressure.

Now a days pressure pipes are mostly used at every places and theyhave eliminated the use of channels, aqueducts and tunnels to a largeextent. These are made of various materials like cast Iron, wroughtIron, steel, cement Concrete, asbestos, cement, timber, etc.. In thetown pips are also used for distribution system. In distribution systempipes of various diameter, having many connections and branchesare used. Water pipe lines follow the profile of the ground water andthe location which is most economical, causing less pressure in pipesis chosen.

Conveyance of Water• The cost of pipe line depends on the internal pressure to

bear and the length of pipe line. Therefore as far as possiblethe hydraulic line is kept closer to the pipe line. In the valleyor low points a scour valve is provided to drain the line andremoving accumulated suspended matter. Similarly at highpoints air relief valves are provided to remove theaccumulated air. To prevent the bursting of pipes due towater hammer, surge tanks or stand pipes are provided atthe end of pipes.

Surge Tank or Surge Chamber

Conveyance of Water

Surge Tank or Surge Chamber

Conveyance of WaterThe selection of material for the pipes is done on thefollowing points• Carrying Capacity of the pipes• Durability and life of the pipe• Type of water to be conveyed and its corrosive effect on the pipe

material.• Availability of funds• Maintenance cost, repair etc..• The pipe material which will give the smallest annual cost or capital

cost will be selected, because it will be mostly economical.

Conveyance of Water

Conveyance of WaterFollowing types of pipes are commonly Used• Cast Iron Pipes• Wrought Iron pipes• Steel Pipes• Concrete Pipes• Cement lined Cast Iron Pipes• Plastic or PVC pipes• Asbestos cement pipes• Copper and lead pipes• Wooden pipes• Vitrified Clay pipes

Conveyance of Water• Out of the types mentioned, plastic or PVC and Asbestos

cement pipes, wooden pipes are not generally used forconveyance of water. They are used in house drainage orwater connection within individual house.

Cast Iron Pipes• Cast – Iron Pipes are mostly used in water supply schemes. They have

higher resistant to corrosion, therefore have long life about 100years.

• Cast Iron pipes are manufactured in lengths of 2.5 m to 5.5 m. Thefittings of these pipes are also manufactured in sand molds havingcore boxes. These fittings are also weighed, coated with coal tar andfinally tested. Cast-Iron pipes are joined together by means of Belland Spigot, Threaded or flanged Joints

Cast Iron Pipes

Conveyance of WaterAdvantages of CI Pipes• Ease in jointing the pipes• Can withstand high Internal pressure• Have a very long design life. (100 years)• They are less prone to corrosion.

Conveyance of WaterDis-advantages of CI Pipes• They are heavy and difficult to transport• Length of pipe available as less (2.5 to 5.5m) so more joints are

required for laying the pipes so chances of leakage also Increases.• They are brittle so they break or crack easily.

Conveyance of WaterWrought Iron Pipes• Wrought Iron Pipes are manufactured by rolling the flat plates of the

metal to the proper diameter and welding the edges. If comparedwith cast Iron, these are more lighter, can be easily cut, threaded andworked, give neat appearance if used in the interior works. But it ismore costly and less durable than cast iron pipes. These pipes shouldbe used only inside the buildings, where they can be protected fromcorrosion. Wrought Iron pipes are joined together by couplings orscrewed and socketed joints. To Increase the life of these pipessometimes these are galvanized with zinc.

Wrought Iron Pipes

Conveyance of WaterSteel pipes• The Construction of these pipes is similar to wrought iron

pipes, it is occasionally used from main lines and at suchplaces where pressure are high and pipe dia is more. Steelpipes are more stronger, have very light weight and canwithstand high pressure than cast iron pipes. They are alsocheap, easy to construct and can be easily transported.

Steel pipes

Conveyance of Water• The disadvantages of these pipes is that they cannot withstand

external load, if partial vacuum is created by emptying pipe rapidly,the pipe may be collapsed or distorted. These pipes are much affectedby corrosion and are costly to maintain The life of these pipes is 25 to50 years, which is much shorter as compared to cast Iron Pipes Steelpipes are not used in distribution system, owing to the difficulty inmaking connections.

• The joints in steel pipes may be made of welding or riveting,longitudinal lap joints are made In riveted steel pipes up to 120 cmdia

Conveyance of WaterConcrete Pipes• These pipes may be precast or Cast-in-situ plain concrete

pipe may be used at such places where water does not flowunder pressure, these pipes are jointed with Bel &SpigotJoints. Plain Concrete pipes are up to 60 cm dia only, aboveit these are reinforced.

Concrete Pipes

Conveyance of WaterAdvantages of R.C.C Pipes• Their life is more about 75 years• They can be easily constructed in the factories or at site• They have least coefficient of thermal expansion than other types of

pipes . Hence they do not require expansion joints• Due to their heavy weight, when laid under water, they are not

affected by buoyancy, even when they are empty.• They are not affected by atmospheric action or ordinary soil under

normal condition.

Conveyance of WaterDisadvantages of R.C.C Pipes• They are affected by acids, alkalis and salty waters• Their repairs are very difficult.• Due to their heavy weight, their transportation and laying cost is

more.• It is difficult to make connections in them• Porosity may cause them to leak.

Pipe Joints• For the facilities in handling, transporting, and placing in position,

pipes are manufactured in small lengths of 2 to 6 meters. These smallpieces of pipes are then joined together after placing in position tomake one continuous length of pipe.

• The design of these joints mainly depends on the material of the pipe,internal water pressure and the condition of the support

• The bell and spigot joints, using lead as filling material is mostly usedfor cast Iron pipes. For Steel pipes welded, riveted, flanged or screwedjoints my be used.

Various types of Joints which are mostly used, are as follows

• Spigot and Socket Joints or Bell & Spigot Joints• Expansion Joints• Flanged Joints• Mechanical Joints• Flexible Joints• Screwed Joints• Collar Joints• A.C. Pipe Joints

Spigot and Socket Joints•This types of joints is mostly used for cast iron pipes

For the construction of this joint the spigot or normalend of one pipe is slipped in socket or bell mouth endof the other pipe until contact is made at the base ofthe base of the bell.

Spigot and Socket Joints

Spigot and Socket Joints• After this hemp or yarn is wrapped around the spigot end of

the pipe and is tightly filled in the joint by means of yarningiron up to 5 cm depth. The hemp is tightly packed tomaintain regular annular space and for preventing jointedmaterial from falling inside the pipe. After packing of hemp& gasket or joint runner is clamped against the outer edge ofthe bell.

Spigot and Socket Joints• Sometimes wet clay is used to make tight contact between

the runner and the pipe so that hot lead may not run out ofthe joint spaces. The molten lead is then poured into V-shaped opening left in the top by the clamp joint runner.The space between the hemp yarn and the clamp runner isremoved, the lead which shrink while cooling, is againtightened by means of chalking tool and hammer. Now adays in order to reduce the cost of lead certain patentedcompounds of sulphur and other materials and othermaterials are filled in these joints.

Expansion Joints• This joint is used at such places where pipes expand or contract due

to change in atmospheric temperature and thus checks the setting ofthermal stresses in the pipes. In this joints the socket end is flangedwith cast iron follower ring, which can freely slide on the spigot endor plane end of other pipes. An elastic rubber gasket is tightly pressedbetween the annular spaces of socket by means of bolts. In thebeginning while fixing the follower ring some space is left betweenthe socket base and the spigot end for the free movement of the pipesunder variation of temperature. In this way when the pipe expandsthe socket end moves forward and when the pipe contracts, it movesbackward in the space provided for it. The elastic rubber gasket inevery position keeps the joint water tight.

Expansion Joints

Flanged Joint• This joint is mostly used for temporary pipe lines, because the pipe

line can be dismantled and again assembled at other places.• The pipe in this case has flanges on its both ends, cast, welded or

screwed with the pipe. The two ends of the pipes which are to bejointed together are brought in perfect level near one another andafter placing of washer or gasket of rubber, canvas, copper or leadbetween the two ends of flanges is very necessary for securing aperfect water-tight joints. These joint cannot be used at places whereit has to bear vibration of pipes etc..

Flanged Joint

Flexible Joints• Sometimes this joint is also called Bell & Socket or Universal Joint.

This joint is used at such places where settlement is likely to occurafter the lying of the pipes. This joint can also be used for laying ofpipes on curves, because at the joint the pipes can be laid at angle.This is a special type of joint. The socket end is cast in a sphericalshape. The spigot end is plain but has a bead at the other end. For theassembling of this joints, the spigot end of one pipe is kept in thespherical end of the other pipe.

Flexible Joints

Flexible Joints• After this the retaining ring is slipped which is stretched

over the bead. Then a rubber gasket is moved which touchesthe retainer high. after it split cast iron gland ring is placed,the outer surface of which has the same shape as innersurface of socket end. Over this finally cast iron followerring is moved and is fixed to the socket end by means ofbolts. It is very clear that if one pipe is given any deflectionthe ball shaped portion will move inside the socket, and thejoint will remain waterproof in all the position.

Flexible Joints

Mechanical Joints• This type of joints are used for jointing cast Iron, Steel or wrought

Iron pipes, when both the ends of the pipes are plain or spigot. Thereare two types of mechanical joints.

• Dressers- Couplings• It essentially consists of one middle ring, two follower rings and two

rubber gaskets. The two follower rings are connected to-gather bybolts and when they are tightened, they pass both the gaskets tightlybelow the ends of the middle ring. These joints are very strong andrigid and can withstand vibrations and shocks up to certain limit.These joints are mostly suitable for carrying water lines over bridges,where it has to bear vibrations.

Mechanical Joints

Mechanical JointsVictaulic Joint• In this type of joints a gasket or leak-proof ring is slipped over both

the ends of the pipes. This gasket is pressed from both the sides bymean of half iron couplings by bolts. The ends of pipes are keptsufficient apart to allow for free expansion, contraction anddeflection. This joints can bear shocks, vibrations etc.. and used forcast-iron, steel or wrought iron pipe lines in exposed places.

Victaulic Joint

Screwed Joints• The joint is mostly used for connecting small diameter cast iron,

wrought iron and galvanized pipe. The end of the pipes have threadsoutside, while socket or couplings has threads on the inner side. Thesame socket is screwed on both the ends of the pipes to join them. Formaking water tight joints zinc paint or hemp yarn should be placedin the threads of the pipes, before screwing socket over it.

Screwed Joints

Collar Joint• This type of joint is mostly used for joining big diameter concrete and

asbestos cement pipes. The ends of the two pipes are brought in onelevel before each other. Then rubber gasket between steel rings orjute rope socked in cement is kept in the grove and the collar isplaced at the joint so that it should have same lap on both the pipes.Now 1:1 cement mortar is filled in the space between the pipes andthe collar.

Collar Joint

Joint for A.C. Pipes• For jointing small diameter A.C. Pipes the two ends of pipes are

butted against each other, then two rubber rings will be slipped overthe pipes and the couplings will be pushed over the rubber rings. Therubber rings make the joint water-proof.

Laying of Water Supply Pipes• Pipes are generally laid below the ground level, but sometimes when

they pass in open areas, they may be laid over the ground. The pipesare laid in the following way.

• First of all the detailed map of all roads, streets lanes etc., is prepared.On this map the proposed pipe line with all sizes and length will bemarked. The position of existing pipe line, curb lines, sewer lines etc..will also be marked on it. In addition to this position of valves andother pipe specials, stand posts etc.. will also be marked, so that atthe time of laying there should be no difficulty in this connection.

Laying of Water Supply Pipes• After the general planning, the center line of the pipe line will be

transferred on the ground from the detail plan. The center line willbe marked by means of stalkes driven at 30 m interval on straightlines. On curves the stalkes will be driven at 7 to 15 m spacing. If theroad or streets have curbs, the distance of center of pipe line fro curbwill be marked.

Laying of Water Supply Pipes• When the center line has marked on the ground the excavation for

the trenches will be started. The width of the trench will be 30 cm to45 cm more than the external diameter of the pipe. At every joint thedepth of excavation will be 15 to 20 cm more for one meter lengthfor easy joining of the pipes. The pipe lines should be laid more than90 cm below the ground so that pipe may not break due to impact ofheavy traffic moving over the ground

Laying of Water Supply Pipes

Laying of Water Supply Pipes• After the excavation of trenches the pipes are lowered in it. The pipe

laying should start from lower level and proceed towards higherlevel with socket end towards higher side. The jointing of pipesshould be done along with the laying of pipes.

• After laying the pipe in position, they are tested for water leakageand pressure.

• When the pipe line is tested, the back filings of the excavatedmaterial will be done.

• The soil which was excavated is filled in the trenches all around thepipes and should be well rammed. All the surplus soil will bedisposed off and the site should be cleaned.

Hydrostatic Test• After laying the new pipe line, jointing & back filling, it is subjected

to the following tests:• Pressure Tests at a pressure of at least double of maximum working

pressure, pipe joints shall be absolutely water tight.• Leakage Test (to be conducted after the satisfactory completion of the

pressure test) at a pressure as specified by the authority for aduration of two hours.

• In this way error in workman ship will be found immediately andcan be rectified. Usually the length to be tested is kept up to 500 m.

Hydrostatic Test

Pumps for Lifting Water• The function of the pump is to lift the water or any fluid at higher elevation or

higher pressure. In water works pumps are required under the followingcircumstances.

• At the source of water to lift the water from rivers, streams, wells etc.. and topump it to the treatment works.

• At the treatment plant to lift the water at various units so that it may flow inthem due to the gravitational force only during the treatment of the water.

• For the back washing of filters and increasing their efficiency.• For pumping chemical solution at treatment plants.• For filling the elevated distribution reservoirs or overhead tanks• To increase the pressure in the pipe lines by boosting up the pressure.• For pumping the treated water directly in the water mains for its distribution.

Pumps for Lifting Water

Classification of pumps• (i) Classification based on principles of operation• Displacement pump• Centrifugal pumps• Air –lift pumps• Impulse pumps• (ii) Classification based on type of power required• Electrical driven pumps• Gasoline engine pumps• Steam engine pumps• Diesel engine pumps

Classification of pumps• (iii) Classification based on the type of services• Low lift pumps• High lift pumps• Deep-well pumps• Booster pumps• Standby pumps

The selection of a particular type of pumps depend upon the following factors

• Capacity of pumps• Number of pump units required• Suction conditions• Lift (total head)• Discharge condition, and variation in the load• Floor space requirement• Flexibility of operation• Starting & priming characteristics• Initial cost and running costs

Displacement Pumps• In these types of pumps vacuum is created mechanically by

the movable part of the pumps. In the vacuum first thewater is drawn inside the pumps, which on the return ofmechanical part of the pump is displaced and forced out ofthe chamber trough the valve and pipe. The back flow of thewater is prevented by means of suitable valves.

Displacement Pumps• The following are the two main type of displacement pumps(i) Reciprocating Pumps(ii) Rotary Pumps

Displacement PumpsReciprocating Pump• Reciprocating pumps may be of the following types• Simple hand-operated reciprocating pump• Power operated deep well reciprocating pump• Single-acting reciprocating pump• Double-acting reciprocating pump

Reciprocating Pump

Displacement PumpsRotary Pump(a) Rotary pumps with gear(b) Rotary pumps with cams• The revolving blades fit closely in the casing and push the water by

their displacement. The blades revolve in a downward direction atthe Centre and the water is carried upward around the side of thecasing. In this way the water is pushed through the discharge pipeand partial vacuum is created on the suction side. The intensity ofvacuum mainly depends on the tightness of the parts.

Rotary Pump

Displacement PumpsAdvantages of Rotary Pumps• They do not require any priming as they are self-primed.• The efficiency of these pumps is high at low to moderate heads up-to

discharge of 2000 l/m• These pumps have no valves, are easy in construction and

maintenance as compared with reciprocating pumps.• These pumps give steady and constant flow• These pumps are deployed for the individual building water supply

and for fire protection.

Displacement PumpsDisadvantages of Rotary Pumps• The initial cost of these pump is high• Their maintenance cost is high due to abrasion of their cams and

gears.• They cannot pump water containing suspended impurities as the

wear and abrasion caused by the impurities will destroy the sealbetween the cans and the casing.

Centrifugal Pumps• These pumps work on the principle of centrifugal force,

therefore, they are called centrifugal pumps. The waterwhich enters inside the pump is revolved at high speed bymeans of impeller and is thrown to the periphery by thecentrifugal force.

Centrifugal Pumps

Centrifugal PumpsAdvantages and Disadvantages of Centrifugal Pumps• The centrifugal pumps have the following advantages• Due to compact design, they require very small space.• They can be fixed to high-speed driving mechanism• They have rotary motion due to which there is low or no noise• They are not damaged due to high pressure

Centrifugal PumpsDisadvantages of centrifugal pumps• They require priming• The rate of flow of water cannot be regulated.• Any air leak on the suction side will affect the efficiency of the pump.• They have high efficiency only for low head and discharge.• The pump will run back, if it is stopped with the discharge valve

open.

Design of Pumps• Design of pumps means to find out the capacity of the pump

required to deliver specific quantity of water against specific head.• So design of pumps can be divided into two parts• To find the total head against which the pump has to operate.• The total power requirement or the capacity of the pump or the size

of the pump required and also deciding the number of pumpsrequired as well as stand by.

Total Head Or Lift Against Which The Pump Has To Work

• The total head or total lift against which the pump has to workincludes suction lift (or Head), discharge or delivery lift (or Head)and total loss of head due to friction, entrance, exit, fitting etc. insuction and rising main.

• If Hs= Suction lift or Head• Hd= Delivery or discharge head• Hl= Total loss of head then,• The total head against which the pump has to work is given by:• H= Hs + Hd + H l


• Suction lift : It is the difference between the lowest water and thepump

• Discharge lift or delivery Head: It is the difference between the pointof discharge or delivery and the pump.

• Generally only the friction losses is considered for the design asminor losses are very small if the length of the pipe is greater


• Friction loss can be found out by Darcy Weisbach equation• Darcy Weisbach Eqn = Hf= 4 f l v2 = f’ l v2

2 g d 2g dWhere ,l= length of piped= dia of pipev= velocity of flowf= coefficient of frictionf’= friction factor Value of friction factor varies between (0.02 to 0.075)

Power required by the pump or capacity of pump

• The horse power (H.P.) of the pump can be determined by calculating thework done by the pump in raising the water up to the height H.

• Let the pump raise W kg of water to height H meter.• Then the work done by the pump= W x H (m.kg)• = ϒ Q H (m. kg/sec)• Where, ϒ = Unit Weight of water• Q= Discharge to be pumped in m3 /sec• H= Total head in meter• Water Horse Power (WHP) = ϒ Q H

75

Power required by the pump or capacity of pump

• Brake Horse Power (B.H.P) = W.H.PȠ

= ϒ Q H75 Ƞ

Number of Pumps, size and stand by units• Pumping units at water works are generally not operated at full

capacity for all times. Since the efficiency of pumping unit varieswith the load, it is a usual practice to design a pumping station thatsome of the pump units can be operated at full capacity, at all thetime. Hence two, three, or four pumps are installed. The sizes of thesepumps can be fixed by considering the demand, available storage.

• Thus, there will always exist some stand by capacity to take care ofthe repairs, breakdowns, etc. Generally 100 % stand-by by capacityto take care against average demand and 33.33 to 50 % standbycapacity against the peak demand is considered sufficient and maytherefore be provided at the pumping station.

Design of Rising Main

Design of Rising Main• Rising main is the pipe through which the pumped water is sent

further to the next unit for treatment purpose. Water flows in thispipe under high pressure and flow is turbulent. Here the friction lossin the pipe is more due to high velocity. Pressure pipes are designedsuch that overall cost of the project should be lowest possible bothfrom maintenance and constructional point of view.


Economic diameter of rising main• For pumping a particular fixed discharge of water, there are two options• It can be pumped through bigger diameter pipe at low velocity• Through lesser diameter pipe at high velocity• If the dia of the pipe is increased, it will lead to higher cost of the pipe line on the other

hand if the pipe diameter is reduced the velocity would increase which will lead tohigher frictional head loss and will require more Horse Power for pumping, therebyincreasing the cost of pumping, also cost of fitting will increase.

• For obtaining the optimum efficiency, it is necessary to design the diameter of thepumping main which will be overall most economical in initial cost as well asmaintenance cost for pumping the required quantity of water. The diameter whichprovide such optimum condition is known as “economic diameter” of the pipe.


• An empirical formula given by lee is commonly used for determining the dia of the pumping or rising main

• D= 0.97 to 1.22 √Q• Where,• D= Economic dia of pipe in meters• Q= Discharge to be pumped in cumecs

Design of Rising MainHead loss in rising main• The loss of head in the rising main can be found by using• (i) Darcy Weisbach eq• (ii) Hazen William’s equation• Darcy Weisbach Eqn= Hf= 4 f l v2 = f’ l v2

2 g d 2g dWhere ,l= length of piped= dia of pipev= velocity of flowf= coefficient of frictionf’= friction factor Value of friction factor varies between (0.02 to 0.075)

Design of Rising MainHazen Williams Equation• V= 0.85 CH R 0.63 S 0.54

• Where,• V= velocity of flow• S= Slope of H.G.L• = Hl = Head Loss

L Length of PipeR= Hydraulic mean Radius of the pipe = A

PIf pipe is running full thenR= ∏/4 d2 = d/4

∏ dCH= Hazen William’s coefficient which depends on age, quality and material of pipe.

Examples• Find out the head loss due to friction in a rising main from the

following data:• Length of the rising main= 600 m• Diameter of pipe= 0.2 m• Discharge required to be pumped = 1200 l/min• Friction factors= 0.025

Examples• Velocity of flow = Q

AQ= 1200 l/min= 1200 x 10-3 m3 /sec

60= 0.02 m3 /secV= 0.02∏ (0.2) 2 = 0.637 m/sec4

Examples• Hf= f’ lv2

2gd= 0.025 x 600 x (0.637)2

2 x 9.81 x 0,2= 1.551 m

Examples• A city with 1.5 lakh population I to be supplied water at 100 lpcd

from a river 1 km away. The difference in water level of sump andreservoir is 30 m. if the demand has to be supplied in 8 hr.,determine the size of the main and B.H.P of the pumps required.

• Take f- 0.0075, velocity in the pipe as 2.0 m/sec and efficiency ofpump as 75 %

Examples• Population of a city= 1,50,000• Rate of water supply= 100 lpcd• Therefore the average demand of the town= 1,50,000 x 100• = 15 x 10 6 l/day• Maximum daily demand= 1.5 x avg demand• = 1.5 x 15 x 10 6

• = 22.5 x 10 6 l/day• = 22.5 MLD

Examples• As the full demand is to be supplied through pumps in 8 hrs• Discharge required= 22.5 x 10 6 l/ hours• 8• = 22.5 x 10 6 x 10 -3= 0.781 m3 /sec

8 x 3600

Examples• The maximum velocity in the pipe is given as 2.0 m/sec• Therefore Cross sectional area of the pipe required• A= Q = 0.781 = 0.39 m 2

• v• If d is the dia of the pipe then• ∏ d 2 = 0.39

4D= 0.704m= 0.75 mTotal lift is given as 30 m

Examples• Friction loss hf can be found by using Darcy Weisbash eq n• Hf= 4 f l v2

2 g d= 4 x 0.0075 x 1000x (2.0 ) 2

2 x 9.81 x 0.75= 8.155 m

Examples• Thus the total lift against which the pump has to work or lift water• = 30 + 1.155• = 38.155m• BHP of the pump= ϒ Q H

75 Ƞ= 1000 x 0.781 x 38.155

75 x 0.75= 526.75 = 530 HP 1 hp(I) = 745.699872 W = 0.745699872 kW

1 W in ... ... is equal to ...

• 1 kg·m2/s

3

http://en.wikipedia.org/wiki/Kilogram

http://en.wikipedia.org/wiki/Metre

http://en.wikipedia.org/wiki/Second

Example• From a clear water reservoir 3 m deep and maximum water level at

RL 35 m water is to be pumped to an elevated reservoir at RL 80 m atthe constant rate of 9 lakh litres per hour. The distance is 2000 m.Find the economic diameter of the rising main and the water horsepower of the pump. Neglect minor losses and take f=0.01

Example• The Discharge Q= 9 lakh per hour• = 9,00,000 = 0.25 m3 /sec

1000x 60 x 60Economic diameter of rising main can be found byD= 1.22 √Q= 1.22 √0.25= 0.61 m

Example• Maximum Suction Head = 3 m ( depth of reservoir)• Maximum delivery head = (80- 35)= 45 m• (Difference between maximum water level and height of elevated

reservoir)• Suction + Delivery= 3 + 45 = 48 m

Example• Friction Head loss can be found by• Hf= 4 flv 2

2 g DV= Q = 0.25 = 0.855 m/ sec

A ∏ (0.61) 24

Hf= 4 x 0.01 x 2000 x (0.855) 22 x 9.81 x 0.61

Hf= 4.886 mThe total Head = 48 + 4.886 mH= 52.886 m

Example• Water horse power of Pump= ϒ Q H

75= 1000 x 0.25 x 52.866

75= 176.22 HP

References

Water Supply Engineering : By Prof S.K. GargKhanna Publishers

Internet Websites

Thanks…

Collection and Conveyance of Water

Education

Transcript of Collection and Conveyance of Water