Muir Beach Water Conservation Implementation
|Sponsoring Agency||Watershed Alliance of Marin|
|Public or private land?||()|
|Location (lat/lon)||37.8622° N, -122.5814° W|
|Location Description||The community of Muir Beach along State Route 1 in Southern Marin County.|
The Watershed Alliance of Marin, Muir Beach CSD, Muir Beach, and Muir Beach volunteer Fire Department to obtain a grant to implement water conservation measures to offset the deleterious affects of groundwater pumping by Muir Beach CSD. Those measures would include primarily graywater and rainwater catchment systems.
Part 2 - Detail
The project will address the indirect draw down of water in Redwood Creek by the Muir Beach community and Pelican Inn. It will
1. Reverse the loss of water supply in Redwood Creek for highly endangered coho salmon (Of three year classes: 1 year class extirpated, 1 year class removed to a hatchery, 1 year class had only 4 nests). Low levels prevented outmigration and overall fish viability in the drought. Restoration of the Muir Beach wetlands for coho, steelhead and red-legged frogs would be supported by the project and improve water quality for coho salmon survival.
2. Enhance water supply for the community and thousands of tourists in an emergency and where the creek and aquifer is the only supply. Federal and state recommendations include alternative water storage for fire fighting or another emergency that could be obtained by increasing storage. In an emergency, the community has only about 5 days of water stored.
3. Build resilience into a vulnerable system for fish and people and where should the pumps fail, there are approximately five days of supply at the current water usage. Rainwater storage would offset this part of the year and allow the tank to remain filled longer.
We are proposing retrofit of qualifying homes and businesses for graywater systems to an average of $2500 per household= $377,500. That would include re-plumbing, diverters, irrigation augmentation with graywater piping.
The proposal includes the installation of rainwater catchment tanks. (varying sizes to landscape size/type and capacity) to an average of $4200 = $634,200 per 150 homes and 1 business and provides Installation of 2 electric low water composting toilets in the community center (legal in Marin County) $15,000 at $7500.
Two Surveys and two education seminars would be conducted including: 4 community meetings held with the CSD to roll out plans and begin project. Approximate administrative and survey costs: $123,00. to include outreach, management, assessment, and providing recommended certified installers for project.
Conduct surveys, project monitoring and provide educational materials for a comprehensive community water conservation plan and infrastructure that will benefit the community, the coho salmon and steelhead. Total projected savings of water with rainwater catchment and graywater systems, we could save 12,400 gallons per day (pop. 310 - average person uses 40 gallons per day for bathing dishes and laundry ) - or 4,526,000 gallons or 13.90 acre feet per year. This grant will enable the community to protect Redwood Creek and reliant species during this and future droughts while securing water for basic human needs and landscaping while protecting property values.
151 roofs times 1000 square feet = 623 gallons per inch =94,100 gallons per inch community and x 35 average inches per year 3.3 million gallons or 10.13 acre feet. Together the savings of 13.90 acre feet plus 10.13 acre feet would equal 24 acre feet per year of water savings and water left in the hydrologic system of groundwater and the stream. This is an optimistic scenario based on capturing and using all rainwater and dependent on the resident's use and plumbing. Rainwater catchment may not have that potential and is dependent on containment size and frequency of storms and use.
If the project is not implemented extirpation of coho salmon is probably going to occur in the very near future because they are deprived of basic biological migration function of not being able to outmigrate and the water quality and quantity is so degraded. Hanging on by a thread, water supply diminishment can be the difference between survival or mortality for coho salmon in Redwood Creek. Further, federally and state listed impacted species that will be affected include steelhead, red-legged frogs and the tidewater goby.
By not having a sufficient and reliable water supply to accommodate the increasing stressors from climate change and drought that is occurring now, the Muir Beach community may lose their water source or it can be even more severely impacted. Many homes have been expanded in recent years and new properties developed while the water permit hasn’t changed. This trajectory encumbers, limits and threatens the existing homeowners water rights with every expansion and new property. The community does not have resilience or augmentation built into their water plan that protects the water resource and also allows unencumbered use of water.
The water supply that is currently pumped into their tanks will only last for about 5 days at the current rate use. There is no guarantee that with continued climate change and drought that the aquifer will remain viable or that water rights could not be challenged in the future.
The project would benefit the landowners, residents, the coho salmon and steelhead trout. Water quality, temperature and supply would be improved.
Groundwater recharge would be enhanced and because of the flood plain connection to the stream the flows of lower Redwood Creek would improve significantly.
Potentially 14-24 acre feet of water could be left in the system, accessible to fish if the project is realized. The project could prevent the extirpation of coho salmon, steelhead, tidewater goby and red-legged frogs all federally and state listed special status species.
Awareness of water use and habitat impacts by landowners would be increased. Watershed stewardship would be enhanced through presentations and conscious use of water.
The project would enhance resiliency during climate change, the drought and in the event of an emergency such as fire or earthquake.
Landowners would be able to continue to maintain healthy gardens and that would lessen the fire danger.