Quick
look at San Juan County (WRIA 2)
Water Resource Inventory Area 2 (WRIA 2) corresponds with the boundaries of
San Juan County, which is comprised of bedrock islands in the northwest corner
of Washington State.
It is the smallest of Washington's 39 counties. It has a land area of
about 175 square miles and a population of approximately 15,000.
Limited water: new options needed
Ground and surface water are limited in WRIA 2. Ground water can be difficult
to find and extract from bedrock. Existing wells can go dry or become
contaminated with salt water.
Thus, many island residents have to find alternative water sources to meet
their water needs. Some island residents use rooftop rainwater collection
systems for their water supply. For some areas, rainwater may be the only water
resource available.
Water right permitting and rainwater collection
Washington State law requires that any person or entity wanting to use a
portion of the public’s water must obtain a
water
right permit from Ecology. Water resources are defined in state law (RCW
43.27A.020) as all waters above, upon or beneath the surface of the earth.
However, Ecology recognizes that regulating small amounts of rainwater was
probably not the intention of existing law. The problem comes in making a
distinction between small systems that should be exempt from the permitting
process, and the large water systems that could impact existing water rights or
harm the environment. Defining this line has been the sticking point in rain
barrel legislation attempted in the previous five legislative sessions.
Ecology recognizes the benefits of rainwater collection and agrees that many
uses of rainwater are consistent with good water management. Ecology also
recognizes that there is currently a backlog of water right applications to
process. So while the Legislature continues to debate rain barrel legislation,
Ecology has developed a practical solution: regionally specific rain collection
and use permits.
Locally-driven solution to rainwater collections needs
The local Watershed Planning Unit (San Juan County Water Resource Management
Committee) requested that Ecology review WRIA 2’s rainwater collection permit
needs on an accelerated schedule. This request was part of the watershed
management plan, which was developed under the local Watershed Planning process.
In response, Ecology is working with the community to develop a faster and
simpler rooftop rainwater collection permitting process for WRIA 2.
Island-wide rainwater permits for San Juan County
Ecology is working with the San Juan County Water Resource Management
Committee to develop a unique rainwater collection process for WRIA 2.
Permits will be issued on an island-by-island basis rather than on a
resident-by-resident basis. For example, all residents collecting
rainwater on Lopez Island will fall under one rainwater permit. The permit
will be managed by San Juan County.
Under an island-wide permitting system, the San Juan County government will
be authorized to manage local rooftop rainwater collection systems under certain
conditions set by Ecology.
An island-wide permitting system for rooftop rainwater collection will be
quicker and easier than the standard water right permit process. At the
same time it will protect other water right holders and water resources, as well
as meet the permit requirements specified by state law.
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The first of the island-wide permits for Shaw and Lopez Islands are
expected to be available by Spring of 2008. |
Proposed Water Right Permit Conditions and Limits
Under the proposed approach for island-wide rainwater permits, it is
anticipated that permitting may be set up in the following manner:
- Ecology will set the specific collection and use limits based on
island-wide studies of water conditions
- Rooftop collection only
- Domestic water use with minor outdoor gardening
- Home on septic system
- San Juan County government will keep track of those collecting rainwater
and estimate how much they are using through the County’s building code
requirements.
- Rainwater collection for irrigation will require a standard water right
permit. The limitations on capture and use are a result of the findings of a
study by Golder Associates, funded by Ecology, that was completed in July
2007.
Typical rainwater harvesting installationn
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Rooftop rainwater collection uses a system in which rainwater is
collected from a rooftop, drained into gutters and downspouts, filtered
through a leaf screen and/or roof washer, and discharged into a cistern
or storage tank, available for future use.
Typical rainwater harvesting installation From “The Texas Manual on
Rainwater Harvesting,” Third Edition, 2005. Texas Water Development
Board.
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Conditions in San Juan County make it appropriate for rainwater collection
Variable rainfall and dry summers
San Juan County’s water resources are provided by local rainfall. The
rainfall varies from near-drought conditions of about 18 inches per year
(southern Lopez Island) to 48 inches (at the top of Mt. Constitution on Orcas
Island).
During summer months, more water is lost from the soil (through evaporation
and use by plants) than is added by rain. Most streams dry up during the
summer.
Island geology makes it hard to naturally store water
The geology of the islands is primarily bedrock and thin soils. Such terrain
has little capability to absorb rainfall to replenish ground water aquifers. Because of the geology, a large percentage of rainwater runs off into the Puget
Sound unless it can be captured for beneficial use.
Benefits
of rainwater collection
Rainwater collection:
- Reduces the impact on ground and surface water sources, especially
during the summer when water is most in demand.
- Provides an alternative potable/non-potable residential water supply.
- Benefits urban stormwater management because:
- there is less water to deal with (stormwater can increase the amount
of water that runs off hard surfaces, and increase flooding).
- there is less contaminated water (less stormwater carrying potential
contaminants into streams, lakes and the Puget Sound).
Current Status
Ecology is currently helping San Juan County apply for water right permits
for rainwater collection, island by island. The permits will be based on
the results of a rainwater collection impact study completed in July 2007 by
Golder Associates. Results from this study will guide the quantities and use conditions authorized
under the permits.
Public Workshop
A public workshop on San Juan County island-wide rainwater permits will be
held in the near future. An announcement with specific details
will be posted on this website.
Contact
Jeff Bash, Watershed Lead for San Juan County (WRIA 2)
Phone: 425-649-7035
Email:
jbas461@ecy.wa.gov
Andy Dunn, Hydrogeologist
Phone: 425 649-7274
E-mail:
adun461@ecy.wa.gov
Other websites of interest
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Analysis Impacts on Water
Resources of Rainwater Harvesting on San Juan Islands - Technical
Memorandum, Golder Associates Inc. 