Moscow, Long Island Module 2: Water Use and Russia, barrier island fountains Conservation development, NY and kids in urban water • Changes in Urban Streams Barton Springs, Austin, TX • Water Reuse • Household Water Use • Local Issues with Water Supply • Conservation Opportunities • Water Use Regulations Navasink River, NJ Robert Pitt Department of Civil and Environmental Engineering University of Alabama Tuscaloosa, Alabama 35487 River Walk, Dangers of urban waters are well known Austin, TX Confluence Park, Platte River and Cherry Creek, Denver, CO But ….. stormwater can be considered a valuable resource in many situations. 1
Kitazawa Stream, Tokyo The local government authority therefore diverted the stream into an underground culvert. The aboveground area was converted into Kitazawa Stream is an example of a severely degraded urban a promenade with extensive plantings. Recently however, local stream in Tokyo that has undergone extensive modification. The residents have requested the addition of a steam along the stream watershed is 10.5 km 2 and has a population of about promenade. A very small flow (0.02 m 3 /s) of treated wastewater 150,000 people. The rapid urbanization in Tokyo since the 1950s has been pumped from 11 km away to create this new stream (a has resulted in a severe decrease in groundwater infiltration during “two-storied watercourse”). The following shows the changes that rains. This has caused decreased groundwater levels and decreased Kitazawa Stream has undergone as the watershed has developed. the associated natural recharge into urban streams. By the 1960s, This new steam, however small, has created a very important there was almost no natural flow in Kitazawa Stream during dry element in the lives of the residents of this heavily urbanized city. weather. The only flows present in the stream was wastewater Special community organizations have been established to plan from homes. The stream was therefore of extremely poor quality, and manage the area. creating an unsafe and nuisance condition. In addition, the increased development caused frequent flooding. The history of Kitazawa Stream, Tokyo suburb (Fujita 1998) The history of Kitazawa Stream, Tokyo suburb (Fujita 1998) 2
The history of Kitazawa Stream, Tokyo suburb (Fujita 1998) The history of Kitazawa Stream, Tokyo suburb (Fujita 1998) Maximum Concentrations Allowed by Maryland for Different Reuse Categories, Compared to Typical Residential Stormwater Distribution of Maryland Residential Water Runoff (Mallory 1973) Use and Required Quality (Mallory 1973) Constituent (mg/L) AA A B C Typical average residential Class Use Rate of Use Percentage stormwater quality (gal/person/day) of Total and highest use Water Use without treatment Total solids 150 500 500 1500 250 (A) AA Consumption by humans, 6.5 7 food preparation, general Suspended solids - - 10 30 50 (none) kitchen use Turbidity (NTU) 0-3 3-8 8-15 15-20 25 (none) A Bathing, laundering, auto 31.0 36 washing Color (color units) 15 20 30 30 25 (B) B Lawn irrigation 518 gal/day/acre 29 pH (pH units) 7 6 6 6 6 to 9 (AA) Oxygen, dissolved 5 5 4 4 Near saturation (AA) (minimum) C Toilet flushing 24.0 28 Total coliform bacteria 1 70 240 240 >10,000 (none) (MPN/100 mL) 3
California Reuse Guidelines (Metcalf and Eddy 1991) Use of reclaimed water Secondary Secondary Total coliform treatment treatment, bacteria criteria As shown on these tables, residential area and coagulation, (MPN/100 mL, disinfection filtration, and median of daily stormwater can be used to meet at least class disinfection observations) Landscaped areas: golf required 23 A water needs, except for suspended solids, courses, cemeteries, turbidity, color, and coliform bacteria. The freeways Landscaped areas: required 2.2 solids, turbidity and color levels are likely to parks, playgrounds, schoolyards be adequately reduced through storage and Recreational required 23 associated settling, plus possible post-settling impoundments: no public contact filtration. The most serious impediment for the Recreational required 2.2 reuse of stormwater in residential areas is the impoundments: boating and fishing only bacteria levels. Recreational required 2.2 impoundments: body contact (bathing) It is possible to determine the likelihood of supplying needed Metcalf and Eddy (1991) state that primary treatment irrigation water and toilet flushing water (reuse classifications (similar to settling in a storage tank) reduces fecal coliform B and C) from the stormwater generated from roof runoff by bacteria by less than 10%, whereas trickling filtration conducting an urban water budget. This budget requires a (without disinfection) can reduce fecal coliform levels by 85 to knowledge of all water sources and uses, and the associated 99%. Chemical disinfection is usually required to reduce quality requirements. pathogen levels by 99.9+%, as likely needed to meet the above bacteria criteria for even the most basic water uses. Because of the risks associated with potential pathogens, reuse of stormwater in residential areas should only be considered where consumption and contact is minimized, restricting on- site reuse to classifications B and C, and only after adequate disinfection and site specific study to ensure acceptable risks. To further minimize risks, only the best quality stormwater (from a pathogen perspective) should be considered for reuse, such as roof runoff. 4
5 Available Freshwater Resources Small Fraction of all Water
6 Typical US Water Use (gallons/person/day)
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Riparian water law is a common-law idea Water Regulations and Conflicts • Owner of land has the right to withdraw water that is adjacent to the land. “Water flows uphill towards money.” • Water must be returned in a relatively unpolluted Old western US saying condition to ensure that downstream users do not have their water rights violated. • The water must be used on land adjacent to the “Whiskey’s for drinking – water’s for water source, not exported (reasonable use fighting about.” doctrine now allows irrigation). Mark Twain • Evolved through practical use. • Practiced mostly east of the Mississippi River where sufficient water resulted in few conflicts. Appropriation water law adopted Increasing Recognition of Water Rights to Protect the Natural Environment from Roman civil law • Loss of fisheries, wetlands, lakes, and other ecological assets are shifting the balance of power governing water • Owners of land may be denied the right to use, away from agriculture and towards protecting the withdraw water if a more beneficial use is found. natural environment. • Government agencies “appropriate” the water. • Australia’s Murray-Darling river basin states have • Water right can be taken away if better use found, agreed to allocate 25% of the river’s natural flow to or lost if abandoned. maintaining ecological health in the system. • Water can be used away from the source. • 10% of the water from the Central Valley Project in • Common in western states where water is much California is to go for maintaining fish and wildlife more scarce. habitat. 13
34 Countries in Africa, Asia and the Middle East are Classified as Water-Stressed • Occurs when a country’s renewable water supplies drop below about 1,700 m 3 per person. • At this level, it becomes difficult for a country to collect enough water to satisfy all the food, household, and industrial needs of the population. • These countries then begin to import grain (requires about 1,000 tons of water to produce a ton of grain). • Poor countries have the vast majority of the water-stressed populations and they can ill afford imported grains. 14
About 40% of the World’s Population live in Water Basins Shared by more than two Countries King Hussein declared in 1990 that water was the only issue that could Biggest potential problems in Middle East: take him to war with Israel • Jordan River (Israel, Jordan, Syria, and Lebanon) • Nile River (Egypt, Sudan, Ethiopia, Zaire, Uganda, Tanzania, Burundi, Eritrea, Kenya) • Tigris-Euphrates Rivers (Iraq, Syria, and Turkey) 15
Saudi Arabia uses Fossil Groundwater for 40% of their needs “The national security of Egypt is in the hands of the eight other • Groundwater depletion more than 5 billion African countries in the Nile basin.” cubic meters per year and rapidly growing. Boutros Boutros-Gali, when he was Egypt’s Minister of State for Foreign Affairs Water Issues Increasingly Current Serious Water Conflicts Responsible for Armed Conflict • Israel’s unrestricted use of groundwater from the Jordan River basin in occupied • Dispute over the headwaters of the Jordan territories. River helped spark the 1967 Arab-Israeli • Egypt-Sudan agreement totally allocates war. Nile River downstream flow without • Bypass canal project in southern Sudan one reference to upstream needs. factor in continuing civil war. • Construction of dams in Turkey reduce Euphrates water to Iraq to as little as 10% of normal flow, and to 60% for Syria. 16
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