There's no end to the effects that urbanization can have on water bodies. Millions of people; landscape manipulation; waste material; dumping of chemicals and fertilizers; withdrawing water for peoples' uses. As you expect, urbanization rarely improves water quality, but in order to prevent problems, one needs to understand how urbanization affects the local waters.
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Urbanization and Water Quality
To some degree, "urbanization" (people living together in groups), has been taking place since ancient times. As populations rose and people mastered techniques to grow food in fixed locations, groups of people became settlements and then towns and cities. In the United States, the speed of this urbanization picked up after World War II, and now many urban areas are growing at a record pace. What are the effects on the local hydrologic system when a rural area is turned into an area full of housing developments, shopping centers, industrial buildings, and roads?
In the table below, the left side shows changes in land and water use when urbanization occurs, and the right side shows the possible effect on the local water system.
Beginning of urbanization
Change in Land Use:
Remove trees and vegetation. Begin building houses, some with sewers and some with septic tanks. Begin drilling wells.
Effect on Water System:
More storm runoff and erosion because there is less vegetation to slow water as it runs down hills. More sediment is washed into streams. Flooding can occur because water-drainage patterns are changed.
Continuing urbanization
Change in Land Use:
Urbanization is finished by the addition of more roads, houses, and commercial and industrial buildings. More wastewater is discharged into local streams. New water-supply and distribution systems are built to supply the growing population. Reservoirs may be built to supply water. Some stream channels are changed to accommodate building construction. Industries might drill some deep, large-capacity wells.
Effect on Water System:
More pavement means less water will soak into the ground, meaning that the underground water table will have less water to recharge it. This will lower the water table. Some existing wells will not be deep enough to get water and might run dry.
The runoff from the increased pavement goes into storm sewers, which then goes into streams. This runoff, which used to soak into the ground, now goes into streams, causing flooding. Changing a stream channel can cause flooding and erosion along the stream banks. More sewage is discharged into streams that weren't "designed by nature" to handle that much water.
The use of too many large wells can lower the underground water table. This can cause other wells to run dry, can cause saltwater to be drawn into drinking-water wells, and can cause land that was formerly "held up" by underground water to subside, resulting in sinkholes and land subsidence.
Local community takes steps to fix some problems
Change in Land Use:
Improvements in the storm drainage system are made. Wells are drilled to recharge underground aquifers. Projects to reuse wastewater might be started.
Ecological-designed recharge ponds disperse some storm drainage to artificially recharge shallow aquifers.
Effect on Water System:
New storm-drainage systems reduce flooding during storms. Less damage is done to basements, yards, and streets. Water is actually injected into recharge wells to put water back into underground aquifers. Reusing wastewater means less pollution, more water conservation, and additional water for recharging aquifers.
Want to learn more about urbanization and water quality? Follow me to the Urbanization and Land Use and Water Quality website!
Below are related topics about urbanization and water quality.
Water Quality Information by Topic
Urban Land Use and Water Quality
Below are publications associated with urbanization and water quality.
Effects of urban development on stream ecosystems in nine metropolitan study areas across the United States
Strategies for managing the effects of urban development on streams
- Overview
There's no end to the effects that urbanization can have on water bodies. Millions of people; landscape manipulation; waste material; dumping of chemicals and fertilizers; withdrawing water for peoples' uses. As you expect, urbanization rarely improves water quality, but in order to prevent problems, one needs to understand how urbanization affects the local waters.
• Water Science School HOME • Water Quality topics •
Urbanization and Water Quality
To some degree, "urbanization" (people living together in groups), has been taking place since ancient times. As populations rose and people mastered techniques to grow food in fixed locations, groups of people became settlements and then towns and cities. In the United States, the speed of this urbanization picked up after World War II, and now many urban areas are growing at a record pace. What are the effects on the local hydrologic system when a rural area is turned into an area full of housing developments, shopping centers, industrial buildings, and roads?
In the table below, the left side shows changes in land and water use when urbanization occurs, and the right side shows the possible effect on the local water system.
Beginning of urbanization
Change in Land Use:
Remove trees and vegetation. Begin building houses, some with sewers and some with septic tanks. Begin drilling wells.Effect on Water System:
More storm runoff and erosion because there is less vegetation to slow water as it runs down hills. More sediment is washed into streams. Flooding can occur because water-drainage patterns are changed.Continuing urbanization
Change in Land Use:
Urbanization is finished by the addition of more roads, houses, and commercial and industrial buildings. More wastewater is discharged into local streams. New water-supply and distribution systems are built to supply the growing population. Reservoirs may be built to supply water. Some stream channels are changed to accommodate building construction. Industries might drill some deep, large-capacity wells.Effect on Water System:
More pavement means less water will soak into the ground, meaning that the underground water table will have less water to recharge it. This will lower the water table. Some existing wells will not be deep enough to get water and might run dry.The runoff from the increased pavement goes into storm sewers, which then goes into streams. This runoff, which used to soak into the ground, now goes into streams, causing flooding. Changing a stream channel can cause flooding and erosion along the stream banks. More sewage is discharged into streams that weren't "designed by nature" to handle that much water.
The use of too many large wells can lower the underground water table. This can cause other wells to run dry, can cause saltwater to be drawn into drinking-water wells, and can cause land that was formerly "held up" by underground water to subside, resulting in sinkholes and land subsidence.
Local community takes steps to fix some problems
Change in Land Use:
Improvements in the storm drainage system are made. Wells are drilled to recharge underground aquifers. Projects to reuse wastewater might be started.
Ecological-designed recharge ponds disperse some storm drainage to artificially recharge shallow aquifers.Effect on Water System:
New storm-drainage systems reduce flooding during storms. Less damage is done to basements, yards, and streets. Water is actually injected into recharge wells to put water back into underground aquifers. Reusing wastewater means less pollution, more water conservation, and additional water for recharging aquifers.Want to learn more about urbanization and water quality? Follow me to the Urbanization and Land Use and Water Quality website!
- Science
Below are related topics about urbanization and water quality.
Water Quality Information by Topic
What is in that water that you just drank? Is it just hydrogen and oxygen atoms? Is it safe for drinking? All water is of a certain "quality" (and you can't tell by just looking), but what does "water quality" really mean? Water full of dirt and grime might work fine for a tomato plant but would you want to drink it? Water quality can be thought of as a measure of the suitability of water for a...Urban Land Use and Water Quality
Wherever you live, there’s a creek or stream near you. The eighty percent of Americans who live in metropolitan areas are often unaware of the network of urban creeks—many teeming with life—that weaves through our cities and town. Nowhere are the environmental changes associated with urban development more evident than in urban streams. - Publications
Below are publications associated with urbanization and water quality.
Effects of urban development on stream ecosystems in nine metropolitan study areas across the United States
Urban development is an important agent of environmental change in the United States. The urban footprint on the American landscape has expanded during a century and a half of almost continuous development. Eighty percent of Americans now live in metropolitan areas, and the advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the dAuthorsJames F. Coles, Gerard McMahon, Amanda H. Bell, Larry R. Brown, Faith A. Fitzpatrick, Barbara C. Scudder Eikenberry, Michael D. Woodside, Thomas F. Cuffney, Wade L. Bryant, Karen Cappiella, Lisa Fraley-McNeal, William P. StackStrategies for managing the effects of urban development on streams
Urban development remains an important agent of environmental change in the United States. The U.S. population grew by 17 percent from 1982 to 1997, while urbanized land area grew by 47 percent, suggesting that urban land consumption far outpaced population growth (Fulton and others, 2001; Sierra Club, 2003; American Farmland Trust, 2009). Eighty percent of Americans now live in metropolitan areasAuthorsKaren Cappiella, William P. Stack, Lisa Fraley-McNeal, Cecilia Lane, Gerard McMahon