THREATS TO CREEK HABITAT:
3. Declining Flows

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Maximum total surface diversion from creeks in the San Francisquito watershed:

2300 acre-feet per year *

* Source: State Water Resources Control Board, Division of Water Rights. Actual diversion depends on availability and need of water and is often less than the maximum value. One acre-foot can is roughly as the amount of water needed to cover a football field one foot deep.


Flows in the creeks of the San Francisquito watershed can be reduced in two ways, by surface water diversion and groundwater extraction. Surface diversion involves taking water directly out of the creek, while groundwater extraction occurs when water is pumped from wells drilled into the water table.

Surface water diversion and groundwater extraction can have detrimental effects on the creek. Surface water diversion can decrease creek levels and drastically alter the habitat of aquatic and riparian species living in and near the creek. Groundwater extraction from the many wells in the groundwater basin area, even those not immediately adjacent to the creek, can have the cumulative effect of lowering the water table, which keeps water in pools through the summer in many of the upper watershed tributaries.

Balancing the water needs of both humans and wildlife is a continuing challenge in the watershed. This challenge will only increase as demands for water throughout California continue to increase.
 
San Francisquito Watershed Council 3921 East Bayshore Road, Palo Alto, CA 94303 650-961-1035 info@sanfrancisquito.org
The San Francisquito Watershed Council receives 501(c)3 fiscal sponsorship from Acterra: Action for a Sustainable Earth