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Small Dams

Planning, Construction and Maintenance

By Barry Lewis

CRC Press – 2014 – 210 pages

Purchasing Options:

  • Add to CartHardback: $89.95
    978-0-415-62111-3
    November 29th 2013

Description

Small Dams: Planning, Construction and Maintenance has been written to provide a practical approach and guide to determining catchment yield and the amount of water required in a dam, advising on selecting and working with engineers and contractors, as well as outlining the cause of dam failures and how to remedy problems quickly. It also covers relevant legislation, environmental and ecological issues.

Employing the principles in this book, in conjunction with heeding the advice of suitably experienced and qualifi ed engineers and contractors, will reduce the risk of failure and help to ensure the long term success of any small dam in question. Small Dams will be an invaluable resource for anyone who owns a dam, and a useful reference for agencies, contractors and engineers.

The author, Barry Lewis, has over forty years of experience as an engineer and has written extensively on farm dams, soil conservation, catchment management and the environmental impact of dams both on and off streams. He was also directly involved in the licensing and regulating of small dams in Australia.

Contents

Section 1 Planning

1.1 Assessing water needs

1.1.1 Planning water supplies

1.1.2 Water quality

1.2 Assessment of catchment yield

1.2.1 Factors controlling catchment yield

1.2.2 Methods of estimating catchment yield

1.2.3 How trees affect yield

1.2.4 Artificial catchments

1.3 Dam site selection

1.3.1 Choosing a dam site

1.4 Types of farm storages

1.4.1 Gully dams

1.4.2 Hillside dams

1.4.3 Ring tanks

1.4.4 Turkey’s nest tanks

1.4.5 Excavated tanks

1.4.6 Weirs

1.4.7 Off-waterway storages

1.5 Dam storage size

1.5.1 Evaporation losses

1.5.2 Ways of controlling evaporation

1.5.3 Seepage losses

1.5.4 Average water consumption

1.6 Using a dam in drought

1.7 Fire fighting

1.8 Small dams and trees

1.9 Dam cost justification

Section 2 Investigation

2.1 Soil testing

2.1.1 Foundation

2.1.2 Borrow pit for embankment material

2.1.3 Spillway site

2.2 Site selection criteria

2.2.1 Seepage losses

2.2.2 Stability of dam sides

2.2.3 Sedimentation in dams

2.3 Foundation materials

2.4 Embankment materials

2.5 Site investigation of materials

2.5.1 Soil texture tests

2.5.2 Unified soil classification

2.6 Analysis of soil

2.6.1 Core trench

2.6.2 Embankment soil

2.7 Location of soil

2.8 Unsuitable material

Section 3 Design

3.1 Items that need to be considered

3.1.1 Embankment types

3.1.2 Core trench

3.1.3 Embankment batter slope

3.1.4 Crest width

3.1.5 Freeboard

3.1.6 Alternative ways of batter protection

3.1.7 Topsoil cover

3.1.8 Fencing

3.2 Flood flow estimation

3.2.1 Peak flow estimation

3.3 Outlet structures

3.3.1 Earth spillways

3.3.2 Design spillway capacity

3.3.3 Selecting spillway dimensions

3.3.4 Chute spillways

3.4 Pipelines through embankments

3.4.1 Trickle pipes

3.4.2 Drop inlet structures

3.4.3 Cut-off collars

3.5 Earth and water computations

3.5.1 Embankment material

3.5.2 Floor slope

3.5.3 Area beneath embankment

3.5.4 Excavated tanks

3.5.5 Water storage capacity computations

3.5.6 Storage excavation ratio

3.6 Estimate of costs

3.6.1 Economics

3.6.2 Dam quality pays over time

Section 4 Documentation

4.1 Collation of plans and specification

4.2 Collecting basic design data

4.2.1 Catchment map

4.2.2 Location (topographical) map

4.2.3 Profiles and cross-sections

4.2.4 Soils

4.3 Assembly of data

4.3.1 Analysis of data

4.3.2 Design

4.4 Construction documents and drawings

4.4.1 Specifications

4.4.2 Checklist

4.5 Final review and approval

4.5.1 Records

Section 5 Construction

5.1 Approval for dam building

5.1.1 Details that may need to be submitted

5.1.2 Referral dams

5.2 Selecting your dam builders

5.2.1 Selecting an engineer

5.2.2 Details that an engineer can provide

5.3 How to build a dam

5.4 Steps in constructing a dam

5.4.1 Setting out

5.4.2 Diversion of water

5.4.3 Clearing and grubbing

5.4.4 Stripping topsoil

5.4.5 Core trench

5.4.6 Borrow pit material

5.4.7 Selection and placing of material

5.4.8 Spillway and outlet structures

5.4.9 Batters and topsoil

5.5 Compaction

5.5.1 Compaction when constructing a dam

5.5.2 Recommendations for compaction

5.6 Soil moisture

5.6.1 Adjusting soil moisture

5.7 Allowance for settlement

5.8 Equipment

5.8.1 Rollers

5.8.2 Features of roller compaction

5.8.3 Other machinery

5.9 Installation of outlet pipe

5.9.1 Testing of the pipe

5.9.2 Foundations on rock

5.10 Checking for compliance with standards

5.10.1 Checking the contractor’s work

5.10.2 Inspection during construction

5.10.3 Good work takes time

5.10.4 Extra ‘bonuses’

5.10.5 Changing your mind

5.10.6 Progress payments

5.11 Final inspection and measurements

Section 6 Maintenance

6.1 Safety surveillance

6.1.1 Equipment for inspection

6.1.2 Observations to be recorded

6.2 Inspection procedures

6.2.1 General techniques

6.2.2 Specific techniques

6.2.3 Evaluation of observations

6.2.4 Frequency of inspection

6.3 Causes of dam failures

6.3.1 Dispersive clays

6.3.2 Seepage and leakage

6.3.3 Cracking and movement cracks

6.3.4 Erosion

6.3.5 Deformation and movement

6.3.6 Defects in associated structures

6.3.7 Vegetation

6.3.8 Total catchment protection

6.3.9 Weed control

6.4 Dam leakage

6.4.1 Rebuilding

6.4.2 Use of soil additives

6.4.3 Artificial liners

6.4.4 Using a clay liner

Section 7 Water

7.1 Quantity

7.2 Water quality

7.2.1 Domestic use

7.2.2 Stock water

7.2.3 Irrigation water

7.3 Water treatment for human consumption

7.4 Algae in farm water supplies

7.4.1 Problems

7.4.2 Identification

7.5 Salt in dam water

7.5.1 Minimising salinity in dams

7.5.2 Interception of sub-surface saline water

7.5.3 Maintenance

7.5.4 Downstream effects

7.5.5 Minimising the effects of evaporation

7.5.6 Stock and salty water

Section 8 Ecology

8.1 Wildlife and plants in dams

8.1.1 Water regime

8.1.2 Basic topography

8.1.3 Vegetation

8.1.4 Grazing by stock

8.1.5 Waterways and swamps

8.1.6 The role of hunting

8.1.7 Waterfowl management

8.2 Water plants in dams

8.2.1 Aquatic plants

8.3 Using herbicides near water

8.3.1 Hazards

8.4 Vegetation on and around dams

8.5 Yabbies

8.5.1 Physical removal

8.5.2 Biological removal

8.5.3 Chemical control

Section 9 Commercial

9.1 Fish farming

9.1.1 Established freshwater species

9.1.2 Dam conditions that control productivity

9.1.3 Feeding

9.1.4 Aquatic vegetation

9.1.5 Fish loss by escaping

9.1.6 Muddy water

9.1.7 Algae

9.1.8 Other species

9.2 Yabby farming

9.2.1 Types of dams for yabby production

9.2.2 Water properties

9.2.3 Stocking and feeding

9.2.4 Harvesting

9.3 Native fauna and total ecosystem management

9.3.1 Native fauna

9.3.2 Managing predation by native fauna

9.4 Licensing process

9.4.1 Licences required

9.4.2 Other steps that may need to be taken

Section 10 Legal

10.1 Legal and policy aspects in Australia

10.2 Liability

10.3 Responsibility of dam owners

10.3.1 Liabilities of dam owners

10.3.2 Permission to build a dam

10.4 Dam failure

10.4.1 Potential hazard and risk of small dams

10.4.2 Minimising the risk of dam failure

10.4.3 In case of dam failure

10.4.4 Abandonment of small dams

10.5 Designer and earthmoving contractor(s)

10.6 Property insurance

References and suggested further reading

Appendix 1 Glossary of terminology

Appendix 2 Engineering specification for an earth-fill farm dam

Appendix 3 Metric and imperial conversion tables

Author Bio

Barry Lewis has over thirty years of experience as an engineer and has written extensively on farm dams, soil conservation, catchment management and the environmental impact of farm dams both on- and off-stream. He is directly involved in the licensing and regulation of farm dams in Victoria, Australia.

Name: Small Dams: Planning, Construction and Maintenance (Hardback)CRC Press 
Description: By Barry Lewis. Small Dams: Planning, Construction and Maintenance has been written to provide a practical approach and guide to determining catchment yield and the amount of water required in a dam, advising on selecting and working with engineers and contractors, as...
Categories: Civil, Environmental and Geotechnical Engineering, Soil Mechanics, Water Engineering