Roofwater Harvesting In California: Obstacles and Opportunities

EXECUTIVE SUMMARY

In response to California’s declining salmonid populations, the worsening water crisis, climate change, and the need for greater community resiliency, Brian Cluer of the National Oceanic and Atmospheric Administration (NOAA) asked OAEC’s WATER Institute to host a brainstorm session Nov. 13th, 2010. This meeting was called to discuss the obstacles to and opportunities for adoption of roofwater harvesting in California.The invitee list included representatives or staff from NOAA, non-governmental organizations, contractors, environmental non- profits and the state water board.This meeting produced a broad overview of the status of roofwater harvesting in California, which investigates obstacles, proposes solutions, offers recommendations for next steps and provides resources for further research.The views expressed in this report are those of the OAEC WATER Institute and do not necessarily reflect those of the meeting participants or NOAA. The findings were as follows.

While salmonids in California face extinction for many reasons, this report will focus on the seasonal extremes of available water quantity.

• Instream flows are lowest when human demand for water is highest, resulting in unsurvivable water levels for salmonids during the dry season.
• Excess winter runoff volume and velocity cause sedimentation and habitat destruction.

Ensuring salmonid recovery requires attenuation of this seasonal hydrograph.

Roofwater harvesting works because in salmonid-bearing areas of California winter rainfall volume is more than sufficient to support both human and salmonid needs, if water is retained during the winter and used during the dry season. Due to this availability of water, we consider these areas to be storage scarce, not water scarce. Roofwater harvesting is a proven solution that offsets human pressure on surface diversions and shallow gallery wells, improves base flows and reduces excess runoff and discharge in winter.

Despite its potential, roofwater harvesting faces significant obstacles to adoption, and we propose the following solutions:

• Citizens and regulators are unaware of roofwater harvesting and its potential for indoor and outdoor use. Education and advocacy are needed in all social and economic arenas.
• State regulations lack roofwater harvesting language, and agencies lack enforcement capacity. Add language to existing laws and improve enforcement capacity.
• Users perceive the permitting and design process as overly costly and time-consuming, while regulators worry that there are insufficient safeguards in place. Reduce permitting cost and time,and educate regulators about benefits and risks.
• Current data fails to prove the efficacy of roofwater harvesting for indoor use and improved instream flows. Provide funding and support to scientists, and prove efficacy.
• Costs can be prohibitive. Seek long-term funding from all available sources.

Our recommendations are: Support adoption of roofwater harvesting by users who negatively impact dry- season flows in salmonid-bearing watersheds, by conducting scientific studies, re-writing existing water rights law, amending or writing new public policy, educating individuals and agencies, creating statewide programs to fund development and installation, and creating a successful roofwater harvesting industry.

BACKGROUND

Salmonid populations throughout California have collapsed and are facing extinction,with many Evolutionary Significant Units listed as threatened and/or endangered by both the State of California and the Federal Government. This “death by a thousand cuts” has many convergent causes, including dams, over-appropriation, pollution, lack of beaver, winter flooding and catastrophically low summer flows in salmonid-bearing streams.

Such poor stream health, and the consequent destruction of salmonid populations, has occurred in the face of extensive recovery efforts. Many watershed assessments have been performed in the north coast of California, and restoration techniques have been applied including instream structures, passage barrier removal, and mitigation of sediment delivery.While certainly worthwhile, these measures are left high and dry in the summer when human demands deplete the instream flows of critical spawning and rearing tributaries.

Research has shown that demand reduction is the most effective and economical strategy for increased stream flows. But since demand cannot be reduced to zero, and human uses compete with salmonids when stream flows are lowest, water supply augmentation is critical.

Due to the numerous challenges water rights present, channel performance has been highlighted and supply ignored, to the detriment of salmonids. It was only after the total collapse of the salmon fisheries that alternative water supply strategies gained widespread recognition as critical components in salmonid recovery.

Exacerbating the problems of insufficient supply,what water is available in the dry season is over-appropriated. Land use planning agencies have permitted a level of subdivision that is far beyond the water supply’s carrying capacity.The 1974 Joy Road Study states that,“A pilot water study conducted by the StateWater Resources Board… indicates water consumption has reached its maximum and perhaps surpassed it in relation to water recharge… thus, the impact of increased parcelization into small lots would irreparably damage the life support capacity of this area’s groundwater reserves” (Joy Road Study, Sonoma County Planning Department, 1974). An important note is that “groundwater” in this study may actually be underflow and springs that are hydrologically connected to salmonid-bearing streams, extraction of which further decreases base flows. In spite of these findings, Sonoma County continued to subdivide, as did hundreds of other areas all over California, resulting in severe dry-season water shortages.

Winter run-off is another area of concern. Watersheds that have historically supported Coho salmon receive significant winter rainfall. A number of studies in the region, including the Salmon Creek Water Conservation Plan, found that total rainfall and stream discharge in the winter is often several orders of magnitude greater than the total human demand for water in the dry season . An additional study in the Green Valley Creek Watershed demonstrates this relationship between average rainfall and human need (Graph 1).

There is plenty of water available annually, but current land use practices limit the ability of upland soils to infiltrate and retain winter rainfall and release it during the dry season to maintain base flows. Human- modified landscapes, almost without exception, become more impervious to rainfall. This lack of infiltration wastes the abundant winter supply, and increased water velocity results in sedimentation (which suffocates salmon eggs), incised streambeds and habitat destruction.

Properly managed, this currently problematic winter rainfall can be a key to salmonid recovery. If water could be retained and later released to the stream in the dry season, critical base flows could be sustained. Thus, storage is the problem, not supply.

California’s current seasonal flow differential badly needs attenuation. See Graph 2 for an illustration of how evapotranspiration and thus irrigation demand is highest in the months when rainfall is the lowest. Any strategy that can intercept and retain winter flows for use in the dry season will benefit both extremes of the seasonal hydrograph, and potentially improve instream flows when fish need them most.

Roofwater harvesting—capturing, storing and using rainwater that falls on roofs—is ideally suited for this purpose. Roofwater harvesting technology is simple, replicable, and has been applied by numerous cultures for hundreds of years, but California has fallen behind in adoption of this useful strategy. Currently there are examples where roofwater comprises 100% of supply, and countries and US states with worsening drought conditions and increasing total demand on water are supporting roofwater regulation, legislation and implementation. See Appendix 1 for examples from places like Arizona, Hawaii, New Mexico, Texas, the US Virgin Islands and Australia.

Several innovative projects in Northern California (in Humboldt’s Mattole River, SPAWN’s Marin County projects and Sonoma’s Salmon Creek) are demonstrating that roofwater harvesting is an effective means for meeting human needs while reducing demands on dry season stream flows, and warrants expansion into other regions.While proven worldwide, roofwater harvesting still faces significant obstacles to widespread adoption in California.

These obstacles can be loosely divided into two domains: public and private. The public domain is primarily concerned with responsibilities and safeguarding resources—keeping people safe, ensuring adequate flows for aquatic life, providing fair distribution of resources, preventing pollution, and so on. The private domain is primarily concerned with rights and using resources—the right to appropriate,convey and use water as individuals see fit without interference from government, other agencies, or other users. These differing concerns create a breeding ground for unnecessary tension that, almost without exception, requires a clear and obvious win-win situation to resolve.

These solutions do exist. One example is the adoption of roofwater harvesting by municipalities with combined stormwater/sewer systems. Here, roofwater harvesting acts as both a stormwater BMP and a supply augmentation strategy. Flood control, wastewater treatment, agencies supporting endangered salmonids, and water supply companies all share the financial and organizational burden of implementation. This drives cost down for individual agencies while supporting their missions, safeguards the public, and ensures that the private sector receives higher levels of service and supply.

More such solutions are needed in response to declining salmonid populations, climate change and the worsening water crisis. So, NOAA’s Brian Cluer asked OAEC’s WATER Institute to call a brainstorm session Nov. 13th, 2010 to discuss the obstacles to and opportunities for adoption of roofwater harvesting. Present were staff or representatives from NOAA, the state water board, non-governmental organizations, contractors and environmental non-profits.

This document is a result of that meeting, and will explore the obstacles to adoption of roofwater harvesting, and offer solutions to each.

CULTURAL ANALYSIS

Many people are unaware that roofwater harvesting is a legal and viable option here in California. Even with steadily worsening water supply and quality statewide, and escalating interstate feuds over diversions from the Colorado and other rivers, roofwater harvesting still has not become front-page news. Until it does, some means must be found to fill the awareness gap, so policy makers and end users both should be briefed on its potentials.

PROBLEM: Individuals, the business com­munity, policy makers and regulatory enforce­ment agencies are not all aware that roofwater harvesting exists, or that it is a viable option.

SOLUTIONS: Continue promoting the benefits of roofwater harvesting to individuals, agencies and lawmakers by creating a series of targeted campaigns to drive awareness and prove the efficacy of roofwater harvesting. Have a working group conduct a Sonoma/ Marin-wide education campaign to raise awareness of roofwater harvesting and its benefit (for humans and fish) that includes good maps with clear visuals, demonstration sites accessible to the public, and com- pelling case studies that substantiate value to land and business owners. Simultaneously, convince high pro- file figures to endorse the concept, driving acceptance. Conduct a talk/slideshow tour of coastal communities chosen for their readiness to adopt.

RESOURCES: www.salmoncreekwater.org/cs/ Roofwater_Harvesting.pdf, http://www.oaecwater. org/education/roofwater-harvesting-booklet, www. sscrcd.org/rainwater.php, www.harvestingrainwater. com, www.harvesth2o.com, www.builditsolar.com/ Projects/Water/Water.htm, http://raingardens.spaw- nusa.org/index.html

PROBLEM: The CA plumbing code and the State Public Health Department do not recognize the potential of rainwater as a potable source and therefore do not include roofwater harvesting language in their public resources for indoor use.

SOLUTIONS: Create a targeted education campaign for state building officials and the Department of Public Health to drive awareness of roofwater harvesting’s ability to provide safe, potable water, while informing them of the risks inherent in the technology so they can adequately safeguard public health. Amend AB 275 (the Rainwater Capture Act of 2011) to support potable use of roofwater.

RESOURCES: (see both reports on domestic use and public water systems) Texas A & M’s guidelines for In Home Use of Rainwater  California Department of Public Health Division of Drinking Water and Environmental Management

PROBLEM: Many people are not aware of how much water can be captured from their roof.

SOLUTIONS: Educate people about quantity— most people who do the math are surprised at just how much water they can catch, and awareness drives adoption.

RESOURCES: www.rain-barrel.net/rainwater-calculator.html, SPAWN’s stormwater calculator

REGULATORY ANALYSIS

The questions of water rights and policy highlight the uncomfortable public/private divide, even though California does not currently assert water rights authority over roofwater harvesting. Individuals are justifiably concerned they will lose their pre-existing water rights or be burdened with excess bureaucratic processes and costs if they employ roofwater harvesting. Civil servants, with equal justification, are concerned that public resources will be harmed in the classic “tragedy of the commons” if roofwater harvesting is unregulated. To support responsible public agencies in managing water rights, new and existing legislation needs more explicit roofwater language. For a list of entities that exert power over water in California, see Appendix 2.

PROBLEM: Many people fear losing their riparian rights if they employ roofwater harvest­ ing to reduce or stop surface diversions.

SOLUTIONS: Provide free legal advice, using grant funding to hire lawyers for people adopting roofwater harvesting and conservation measures. Publicize the benefits of registering riparian rights, and get agencies to fund development of a roofwater harvesting system in exchange for the landowner entering into a “Riparian to Rain” easement or conservation agreement. Include a forbearance agreement where landowners are allowed to store water for more than 30 days for use during summer months, while an NGO monitors stream flows and water usage. This is being successfully implemented in the Mattole watershed.

RESOURCES:  Water Storage and Forbearance brochure and Legal Options for Streamflow Protection brochure

PROBLEM: Some agencies are not exercising their authority in regulating appropriative and riparian rights and streambed alterations. Riparian users have a disproportionate impact on stream health, but their regulations are minimally enforced, thus they have no incentive to invest in tanks.

SOLUTIONS: Support implementation and enforcement of AB 2121 by the State Water Board, and 1602 permit requirements by the California Department of Fish and Game. Determine why agencies lack capacity to enforce these laws, and help them gain such capacity. For existing diversions, make the 1602 permit program retroactive.

RESOURCES: www.dfg.ca.gov/habcon/1600/qa.html, www.swrcb.ca.gov/waterrights/, http://www.ourstreamsflow.org/ab_2121.html

PROBLEM: Water has been over­appropriated in many basins.

SOLUTIONS: Create an adequate water budget for each watershed. For agencies with available mitigation funds, encourage them to apply these funds toward development of water right conservation easements. Allow end users who have a roofwater harvesting off- set in place to dedicate their water right using the wa- ter trust or conservation easement model. Other in- centives could include a reduced tax bill in exchange for temporarily relinquishing appropriative rights, following the model of the Williamson Act.

RESOURCES: USGS Water Budgets circular, Legal Options for Streamflow Protection brochure, Trout Unlimited’s Liquid Assets by Steven Malloch, The Trust for Public Land’s Water Acquisition Handbook: A Guide to Acquiring Water for the Environment in California (2003).

PROBLEM: Current and proposed legislation lacks roofwater language.

SOLUTIONS: All Senate and Assembly Bills specific to water rights need to include robust, appropriate language about roofwater harvesting. AB 275 (the Rainwater Capture Act of 2011) needs to be amended to support potable use of roofwater. AB 2121 needs to include existing storage and make roofwater harvesting a consideration for diversion structure permits. AB 3030 should promote roofwater harvesting as a demand reduction strategy (eg. Sonoma Valley Groundwater Management Planning Process). AB 1420 (water demand management measures) and AB 1560 (building standards) need rainwater harvesting language as well.

RESOURCES: Lists of statutes, regulations and incentives in USA and abroad: http://www.oaecwater. org/education/roofwater-harvesting-resources, http:// www.harvesth2o.com/statues_regulations.shtml, http://www.harvestingrainwater.com/rainwater- harvesting-inforesources/water-harvesting-tax- credits/

TECHNICAL ANALYSIS

While roofwater harvesting technology is simple and has been implemented worldwide for millennia, California regulators have not yet fully accepted this useful strategy.As a result,end users perceive the permitting and design process as overly complex, while regulators worry that there are insufficient safeguards in place.

PROBLEM: A common belief is that roofwater harvesting will induce growth and sprawl.

SOLUTIONS: Work with land-use planning agencies to develop better growth-regulation tools and encourage the adoption of more serious water conservation measures countywide. Elect a board of supervisors friendly to roofwater harvesting, update city and county general plans to include roofwater harvesting language and hold elected officials account- able for upholding these general plans as passed (such as the Sonoma County General Plan’s Water Resources Element that states “encourage…roof catchment of rainwater…minimizing the need to use potable surface water or groundwater”).

RESOURCES: Sonoma County General Plan WRE Policy WR-4k www.sonoma-county.org/prmd/ gp2020/wre.pdf

PROBLEM: Building codes and zoning re­quirements can add cost and complexity to the permitting process. State building codes require a building permit, and in some cases an engineering approval as well as a grading permit, for any tank larger than five thousand gallons.

SOLUTIONS: Marin and Sonoma Counties have adopted the state regulations and have the option to modify them to make roofwater harvesting easier. Since tanks smaller than five thousand gallons on flat ground for non-potable use require no permits, end users can install multiple small tanks to eliminate permitting requirements. For larger tanks, simplify the permitting process, or raise the size limit for tanks on flat sites. Waive fees for grading permits if the cut or fill is for roofwater harvesting. Counties could subsidize permit costs. Make zoning variances easier to get for roofwater harvesting tanks by educating and enlisting members of the zoning department. Dedicate a county employee to roofwater harvesting permits who will prioritize large storage systems and fast-track permits that include roofwater harvesting.

RESOURCES: Contact your local building department for permitting and zoning requirements, and review the State of Washington’s attempt to streamline roofwater harvesting permits here: www.harvesth2o. com/statues_regulations.shtml#wa

PROBLEM: Backflow prevention device requirement—Any “auxiliary water supply” requires an annually certified double backflow prevention device if connected to municipal supply.

SOLUTIONS: Make the backflow prevention device part of the municipal system to free the end user from maintenance and certification, and put them in at the meter as standard practice for new construction. Consider using an air gap which can cost less, doesn’t require inspection and is not prone to failure.

RESOURCES: American Backflow Prevention Association www.abpa.org, Backflow prevention Links www.nobackflow.com/backflow.htm, On Tap Magazine’s “Controlling Cross Connections,” Fall ’07 issue www.nesc.wvu.edu/ontap.cfm

PROBLEM: Perception that tanks are ugly, too big and there is nowhere to put them.

SOLUTIONS: Provide information on all the options—tanks that snap together into fences, fit under decks or in basements, can be painted, wrapped in wood, poured out of concrete to look like rocks or have vines growing on them.

RESOURCES: Water Storage: Tanks, Cisterns, Aquifers and Ponds by Art Ludwig www.oasisdesign.net/water/ storage, www.tank-depot.com/tanks/rainwater.aspx

PROBLEM: The design process is costly, time­ consuming, and suffers from an absence of professionals experienced in roofwater harvesting design.

SOLUTIONS: Offer free site assessments with land- owners to determine appropriate water conservation and harvesting strategies, conduct installer trainings for builders, and provide assistance and resources to the DIY community. Direct people to the available knowledge base and create programs that offer free technical assistance, like SPAWN’s Ten Thousand Rain Gardens program.

RESOURCES: www.raingardens.spawnusa. org/, http://raingardens.spawnusa.org/calculating- stormwater-runoff.html, ARCSA courses for builders www.arcsa.org/content.asp?pl=4&contentid=4