While previous civilizations were content with settling near water sources, or in areas with greater rainfall, advances in technology and increases in population, have led (a) to the emergence of issues like urbanization, sanitation, control of waterborne diseases, water treatment, depletion, conservation, and reuse, (b) to the extensive study of water resources and water cycles, and (c) to the formulation and implementation of various actions to ensure its appropriate use for human comfort and development.
Recent decades have seen the development of issues like widespread asphalting and concreting in urban areas, sharply increased demands for water on a global basis, increased contamination of naturally available water, disturbances in water cycles because of pollution and global warming, and terrorist threats aimed at contaminating or damaging water storage and supply systems. Water supply, and its availability for human usage, has thus become increasingly vulnerable to diverse forces, forcing administrations and decision makers to respond with short and long term strategies to reduce water vulnerability, now and in the future.
Objective The three county region of Palm Beach, Broward, and Miami-Dade, in Southern Florida, represents one such area in the United States where rapid urbanization, increasing population and significant increases in water consumption have led to increased water vulnerability and to carefully thought out and constructed responses by administrators and policymakers to counter this development, both in the short and long term. This assignment aims to study, assess and analyze the issue on the basis of the following requirements, parameters and assumptions:
¢ Identification of supply and demand factors that, at present, define and affect water supply for specified tri county region on the basis of research. ¢ Identification and assessment of the natural and manmade hazards that can currently affect water supplies in the three counties. ¢ Forecasting of the likely environment, and identification of water supply and demand issues after 60 years, i. e. , in 2067, considering that (a) half the existing square footage of impervious surface is added every 30 years, (b) another 50% of the existing footage is remodeled every 30 years, and, the annual population grows at the rate of 1.
5% annually. ¢ Identification of measures to (a) mitigate adverse impacts to water supply and (b) to adapt buildings to the projected realities of 2067, on the basis of a comparative assessment of water supply vulnerability in 2007 and 2067. The research effort depends primarily upon material available on the subject by way of texts, journals, and magazines, in electronic and print format, as well as on official and other websites. All information sources are available in the bibliography.
The assignment is structured into sections that deal with issues sequentially and thus enable progression of ideas and cohesion of thought. 2. Current Demand and Supply Factors that define and affect Water Supply in the Palm Beach, Broward, and Miami-Dade counties of Southern Florida. The Tri County area in Southern Florida lies in the southeastern tip of the United States, the peninsular finger like landmass that stretches into the oceans, bounded by the Atlantic on the east and the Gulf of Mexico on the west.
Apart from its unique, practically tropical ecosystem, the Tri County area is well known for its diverse ethnic structure, its agricultural produce, its burgeoning population, its rapid urbanization, and its sophisticated and controlled water management system. All these factors, ecological and anthropogenic, have led to opposing environmental stresses, burgeoning demand, and a complex and vulnerable water supply situation. (Blake) a. Demand Demand factors have thus been governed by burgeoning population, increased demand for agricultural water, greater use of recreational facilities, and increased industrial demand.
Demand for water has increased significantly during the last four decades. The population of the tri county area has increased from about 3500 in 1900 to more than five and a half million in 2006, making it one of the most densely inhabited areas of the USA. This sharp growth in population is due, apart from migration from other states and organic growth of local population, to significant immigration influx, which, in turn has led to a multi ethnic and multicultural demographic structure. The present population of 5. 5 million consists of 1.
29 million people living in Palm Beach, 2. 4 million in Miami-Dade, and 1. 79 million in Broward. The population is a mix of white, African American, Hispanic, Native American, and Asian ethnicity, the continuous expansion occurring because of agricultural development and expansion in the early and middle years of the 20th century, its substitution by industry and mining, and extensive urbanization. Water is needed for municipal, agricultural, recreational, industrial, and power generation needs. Usage of water in the Tri County increased, by about 250%, between 1965 and 2000, i.
e. , from 875 to 2140 Mgal/day. (Impact of Anthropogenic Development on Coastal Ground-Water Hydrology in Southeastern Florida, 1900-2000) b. Supply Supply of water in the Tri County area is met in approximately proportions by surficial aquifer and ground water systems. Ground water is the principal source of municipal supply and is obtained from numerous well fields. Water for agricultural purposes comes largely from surface sources in Palm Beach and Miami Dade, and while its requirement had steadily increased until the late 80s, has since declined because of substitution.
Freshwater in the Tri County is limited in quantity and is of inadequate quality. Groundwater has been subjected to surface contamination and by underground saltwater incursion. Some wells are near landfills, treatment plants, and contaminated sites, and are thus vulnerable to increasing contamination. Some areas still rely upon septic tank sanitation and private wells, both of which can cause public health problems. The Tri County area is characterized by high evapotranspiration, periodic floods and droughts, and infrequent hurricanes. Annual precipitation is between 50 to 62 inches.
(Thomas) The Tri County and contiguous areas have had to suffer the development of a controlled water management system, aimed at using land for urbanization and agriculture, and comprising of a widespread system of canals, levees, impoundments, surface-water control structures, and numerous municipal well fields, ¦ used to sustain the present-day Everglades hydrologic system, prevent overland flow from moving eastward and flooding urban and agricultural areas, maintain water levels to prevent saltwater intrusion, and provide ¦ adequate water supply.
(Impact of Anthropogenic Development on Coastal Ground-Water Hydrology in Southeastern Florida, 1900-2000) Fast increasing population and rapid urbanization has led to the development of unprecedented urbanization, with consequent asphalting and concreting of vast tracts of land. In an area dependent upon potable water ground wells for most of its fresh water resource, this has resulted in depletion of surface and intermediate aquifers, because of the forced routing of rainwater, unable to penetrate impervious concretized and asphalted surfaces, through runoffs and drains, into the seas.
(Blake) 3. Identification and Assessment of Natural and Anthropogenic Hazards that can Currently Affect Water Supplies in the Tri County Area. Natural hazards in the area can arise from periodic floods and droughts. In fact, a drought like situation in 2007 has resulted in restriction of water supplies. Palm Beach and Broward are under Phase III water restrictions, with stipulations that outdoor watering should not occur more than once a week, whereas Miami-Dade is under a Phase II restriction. Hurricanes also occur but are reasonably infrequent.
The area has seen massive human intervention for a number of decades, resulting in wide ranging changes to the ecosystem and the development of potentially hazardous situations. Population growth and urbanization have led to changes in the coastal hydrology of the surficial aquifer system. The construction of a complex water management system, involving drainage facilities, large well fields, and levees, along with widespread concretization, has led to the depletion of aquifers and can result in exacerbation of drought like conditions.
The population explosion has put enormous stress on sanitation and water treatment facilities, and there is significant risk of drinking contamination where people still depend upon private wells, especially in areas where septic tanks are still in use. Runoffs from urbanized areas have introduced high level of phosphorus, nitrogen and other contaminants in water bodies, which can certainly pose health hazards if not tackled adequately. These pollutants, along with salt water intrusions can threaten the quality of groundwater, and in fact, have forced new well digging to move westwards, away from the sea.
Ecological damage to existing flora and fauna and to the natural ecosystem has been extensive, resulting in (a) loss and damage of the water from the natural system due to discharge and seepage, (b) drop in wading bird populations, (c) infestation of land with exotic invasive plants and (d) the development of thousands of contaminated (brownfield) sites. (Thomas) Continuous population expansion, currently pegged at 1. 8% annually can also result in further pressure on water supply to the three counties. 4. Forecasting of Situation in 2067 on the basis of Assumptions provided in the Objectives listed in Section 1.
The situation in 2067, sixty years from now, is unpredictable because of the largely unknown consequences of global warming and its effect upon annual precipitation, the periodicity of droughts and floods, temperature fluctuations, and the occurrence of hurricanes. Recent disasters like the Tsunami and Katrina have driven home the point that uncertainties in weather and geological behavior are going to become more pronounced, and while predictability is going to be difficult, implementation of early action warning systems could help in mitigating extensive damage to life and property.
Projections need to be made upon the basis of certain assumptions, and in the Tri County area depend mainly upon population growth. While the average population growth in the past in this region has averaged 1. 8% annually, the forecasted growth of 1. 5% per annum would lead to the following population figures for the Tri County.