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Brief History of Water Systems
• This brief history is adapted from – “Historical Urban Water Systems” by Dr. Robert
Pitt, Department of Civil and Environmental Engineering, University of Alabama, Tuscaloosa, AL 35487
• As we proceed through the history, consider whether the picture is a water control, water use, or environmental restoration system.
Engineering
• “Engineering is the profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to use, economically, the materials and forces of nature for the benefit of mankind.”– NAP, 1985 “Engineering Education and Practice in
the United States: Engineering Technology Education” ISBN 0-309-07826-1
Engineering
• “Engineering is the profession where mathematical and natural science is applied to develop ways to use the materials and forces of nature to benefit mankind” – ABET is credited with this definition, yet the actual
quote is hard to find. The National Academies mentions ABET in the paragraph following their definition, so I will accept the above as ABET’s definition.
Engineering
• “Engineering is innovative application of knowledge to produce something to satisfy human needs”– Voland, G. 2004. “Engineering by Design” 2ed.
Prtentice Hall, 640p. ISBN 0131409190
Engineering
• Invention is neither necessary nor mentioned in the ABET definition. – engineering is systematic – science is systematic
• what are the 5 steps of the scientific method?
Engineering
• Invention is mentioned in the NAP definition but otherwise the definition is a lot like the ABET definition – Develop ways to … – Invent ways to …
Engineering
• Invention is the point of engineering in Voland’s definition – there is, in fact, no mention of systematic
• All three definitions serve the same customer (us!)– ABET: … to benefit mankind – NAP: … for the benefit of mankind– Voland: … to satisfy human needs
Design
• Creation of a solution to a problem– In a practical sense a design might be
• A drawing• A prototype• A report• A program• A set of instructions (recipe)
– Something from nothing that solves a problem
Design
• Things engineers “do” that are “design”– Select of specifications from a manual– Scheduling materials– Populating an input file to run a computer
program– Running a program to produce output to support
a permit application– Writing an operations protocol (a recipe to run
something)
Design
• Design is the management of constraints– Negotiable
• Money• Time• Aesthetics• Performance
– Non-negotiable• Physics• Chemistry
Design Constraints
• Identify and classify constraints• Manipulate design variables to satisfy non-
negotiable constraints and optimize negotiable constraints
Frequency Based Design
• Design to accommodate an event of some pre-determined probability (return frequency).– Assume that more frequent events are also
accommodated.• You did frequency analysis in hydrology! • T-year event
Risk Based Design
• Design to accommodate some pre-determined expected net loss.– Expected loss is product of the probability of
failure and the cost of that failure.
• Design to minimize the sum of initial cost and expected loss
• You did elements of risk analysis in hydrology, namely the probability portion.
Critical-Event Design
• Design to accommodate largest anticipated event.– Applied for systems where consequences of
failure are huge (economically and/or politically)– Large dams, nuclear power plants
• Assumes the event is anticipated– Earthquake + Tunsami + Pump Failure combined
were not anticipated (actually they were, just no-one paid attention!)
Hydrologic Data
• Design uses hydrologic and geologic data and various analysis tools– USGS: topography, streamflow, computer programs– NRCS: soil maps, land use, computer programs– US EPA: rules, chemical properties, computer programs– NCDC: rainfall, snowfall, solar radiation– USBR: Western US water and energy supply– USACOE: Navigable waterways, computer programs– FHWA: design manuals, computer programs
Hydrologic Data
• Design uses hydrologic and geologic data and various analysis tools– TWDB: Funding (for cities and water districts)– TCEQ: Rules, guidelines, some data– TNRIS: Evaporation estimates, digital elevation models,
digital ortho-quadrant maps, false IR images, etc.– TxDOT: Design manuals, some data, computer programs– County: Rules, design manuals, some operate rainfall-
stage networks– Cities: Rules, design manuals
Hydrologic Data
• Design uses hydrologic and geologic data and various analysis tools– River authorities– Drainage districts– Flood control districts– Irrigation districts– Council of Governments (COGs)
Data
• Most data are NOT free– Agencies charge a fee for data, usually pretty
small.– NCDC is worst offender of taking the fee, then
providing the wrong data, so be sure you know what you want.
– A lot of useful data are currently free, but don’t get offended if in the future you expected to pay for it.
Water Control Systems
• Spatial and temporal distribution of surface runoff from rainfall events (drainage engineering)– Flood control– Storm water harvesting
• Capacity is based on AREA served– hydrology dominated designs
Water Use Systems
• Spatial and temporal distribution in support of human habitation– Water supply/treatment/distribution– Waste water collection/treatment/discharge
• Capacity is based on POPULATION served– hydraulic dominated designs
Environmental Restoration Systems
• Spatial and temporal distribution in support of non-human habitation– Create “desirable” conditions
“Desirable” <= Policy <= Value Judgment
Trenching
• Most water distribution and some water collection systems are placed underground.
• Trenching is usually the most efficient way to place systems underground.