Any shunted water system such as irrigation systems and water supplies
for industries, towns and cities.
Keywords
shunted water systems, water supply, water volume, streams,
rivers, water tables, irrigation systems
Predecessor Patterns
. . . (none)
Problem Summary
When water is shunted (detoured into artificial systems) the
volume of water is decreased at the lower ends of the drainage,
in turn decreasing the productivity of downstream waters.
Analysis
The normal use of shunted water has the following effects:
Less water is available for agricultural use downstream.
Fewer people and communities can be supported downstream.
Less productivity of important species of fish for commercial use.
Reduced suitability for downstream recreation.
Examples of this problem include:
Decreased water volume in the Colorado River is causing the
population of stotuava fish and shrimp to decline in the Gulf of
California, both commercially important species for local
communities such as San Filipé, Baja, California, and
Guaymas, Sonora, Mexico.
Decreased water volume in the Nile is causing severe population
decrease of the Mediterranean Sardine.
Decreased water volume in Salmon streams impairs the ability of
adult Salmon to find the stream where they were born. If the waters
from those streams is decreased, they have less of a chance to
locate them (by smell) while migrating offshore.
Decreased water volume in streams decreases the geographic area
of estuaries, which in-turn reduces the fertility of offshore
waters (on the continental shelf). This is especially a problem
along the Eastern seaboard of the U.S. where commercial fishing is
important.
Solution Summary
Therefore:
Maintain the water volume of downstream waters by:
Returning shunted water to the place where it's taken from the
drainages.
Recycling as much shunted water as possible through secondary
and tertiary water treatement facilities.
Conserving the use of water, e.g., using non-atomizing or
non-vaporizing irrigation systems.
Successor Patterns
In semi-arid areas,
Carry-off Irrigation can prevent salinization
while helping to maintain water table levels. . . .
References/Sources
Author/Date
Ken Asplund and Gary Swift, March, 1973; last revision 7/16/96
