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Abstraction of water from surface waters (streams, rivers and lakes), is as old as human existence, and from groundwater (shallow wells, boreholes and aquifers) since humans developed the requisite technologies. The regulation of this activity is a relatively recent development and currently only relates to abstractions of 10 m²/day and greater. This means that smaller abstractions are unregulated. Private wells and boreholes for domestic and small operations are not recorded and many may be abstracting from the same zone of contribution (the geographic land area through which water percolates before recharging to groundwater.) When this happens, the cumulative demand on the zone can cause the supply of water to be severely diminished and the abstraction points to dry up. The cumulative effect of unregulated abstractions from rivers and streams has the potential to cause significant ecological damage. Levels upstream of the abstraction point can be reduced and affect the levels of the feeder streams to the main channel. This in turn can lower the levels in the fish spawning areas (upper stretches and headwaters), to the extent that they expose the spawning beds (redds) and make them unviable. Similarly, unregulated lake abstractions can have the same effect on lake feeder streams.

As a result of the EU Water Framework Directive, recently published River Basin Management Plans include a commitment to the “introduction of strengthened controls on abstractions of water” with   “new WFD-compliant regulations to include a modernised system of registration and prior authorization … ” to be in place at the latest by the end of 2012.  It is vital these regulations address the potential ecological threats posed by unsustainable abstraction and that no deterioration in the ecology or our rivers or lakes occurs before these regulations are in place.

SWAN proposed measures to address abstraction pressures

 

Groundwater Abstractions

  • All existing dug wells (usually shallow wells dug into the upper levels of the water table and liable to winter/summer fluctuations) to be inventoried and recorded.
  • All existing boreholes –  public, private and industrial – to be inventoried and recorded.
  • Zones of contribution to boreholes to be established and mapped.
  • Proposals for abstractions for more than 5m²/day to require an abstraction licence.
  • Proposals for abstractions to be assessed for impact on those zones.
  • Calculations for recharge rates to the zone of contribution (or aquifer) should accompany licence applications.

 

River and Stream Abstractions

  • All existing abstractions should be inventoried and recorded.
  • Casual abstractions (for farming and agricultural purposes) to be reported to the local authority.
  • Proposals for abstractions for more than 5m²/day to require an abstraction licence.
  • Proposals for abstractions to be assessed for impact on the river system above and below the proposed abstraction point.

 

Lake abstractions

  • As for river and stream abstractions above. 
  • Proposals for abstractions to be assessed for impact on seasonal levels in lakes and on feeder streams

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