How does RWC for sole source residential domestic water effect our streams and salmon habitat?
In accordance with Washington State’s instream rule restricting new wells in the Skagit River Basin, some land owners are pursuing rainwater collection as their sole source of water to achieve a building permit. There seems to be gridlock between the Department of Ecology, local tribes, land owners, and the county planning department. Aquifer recharge, instream flow, and salmon habitat are the concerns being discussed. Past studies have shown that rainwater catchment for domestic sole source residential use enables rainwater to infiltrate into the aquifer and benefits the creeks, streams and rivers.
Typically there is more concern with summer rain than winter. According to a 1981 Water Supply Report for Jefferson County “Actual evapotranspiration (portion of water lost to the air or used by plants) exceeds soil moisture utilization.”
In a study, “analysis if rainwater catchment in WRIA 17”, by Kurt Unger PHD. Dept. of Ecology Washington State., “Aquifer recharge occurs predominately in deforested or partially deforested areas due to evapotranspiration rates.”
Ground water is more enhanced by collecting rainwater, it’s domestic use, then recharging the aquifer by a leach field. This is most important during the summer months do to evapotranspiration. Mr. Unger goes on to say ” Given the above analysis, it is the author’s opinion that building permits issued in the WRIA 17 based on rainwater catchment as sole source of supply will not pose a threat to streams. In fact such catchment systems will likely provide hydrological benefits.”
Click here for more information on the WRIA 17 study.
Salmon swimming upstream in Ketchikan Creek courtesy of Wknight94
In a statement posted December 2013, Jack Moore, CBCO building official writes, “Skagit County is legally required to stop issuing building permits and subdivision approvals in the Skagit Basin that rely on new wells, unless Ecology approves a plan for mitigation or a plan for reliance on a alternative water source during times when minimum in stream flow requirements set in WAC 173-503 are not met.”
With the decision of the state legislature in October of 2009, rainwater collection is legal throughout the state with many County Health Departments adopting for potable usage. Rainwater collection for decentralized potable usage has proven to be a safe, reliable source as an “alternate water source”. Skagit County considers rainwater collection for potable use as a policy and can be legally challenged at this time. The system must be designed by an engineer with knowledge in water systems and be approved by the Health Department.
Spawning coho | Photo: Soggydan/Flickr/Creative Commons License
With population growth in the Seattle and surrounding area, the effects of this growth, demand, and aging infrastructure will impact our water and sewer systems economically.
Estimates of costs to upgrade and expand existing systems over the next 20 years are 6.5 billion dollars. According to Luna Leopold, Cascadia Green Building Council, the new “Green Infrastructure Initiative” promotes low- impact development and natural storm water systems.
“It’s our hope that this study, combined with our extensive outreach and advocacy efforts, will spur a broad movement toward more ecological sound water practices and procedures. Greater support for smaller scale, decentralized systems is crucial if we are serious about addressing the negative impacts related to how we manage water and waste.” Explains Jason McLennan CEO of Cascadia Building Council western region.
Click here to read more about Healthy, Resilient Water Systems in the Puget Sound.
Photo: By Grace from Seattle, USA (Puget Sound ferriesUploaded by X-Weinzar) [CC-BY-2.0], via Wikimedia Commons