All posts by Ken Blair

A rainwater collection systems designer and consultant, Ken has designed and installed residential and commercial systems, primarily in the northwest United States for more than 10 years and, in 2014, began consulting and managing builds in other states. Ken is an accredited ARCSA Professional Designer / Installer and Life Member, the Northwest Regional ARCSA representative and advisor to its education committee and is available to speak about Rainwater Collection Systems design and builds. Ken is a United States Navy veteran, having served on active duty during the Vietnam War era. A career entrepreneur, Ken created a new business focus with a commercial dive company in Hawaii in the mid 1980′s to respond to and clean up oil spills, oil spill equipment training, service and maintenance for the oil co-op service industry. Ken is passionate about having a positive impact on the environment and is also a founding director of BANK-ON-RAIN (2011-2014), whose mission is to create grassroots solutions for rainwater collection for consumption and agriculture in developing areas of the planet.
How-to, Rainwater Catchment

Rainwater Collection in Washington State: Where to Begin?

gutter-484684_640We want to keep our families safe, but when we read stories about sustainability, water conservation, saving the environment, aging infrastructure, even poisoned public water systems – how on earth are we supposed to know where to begin when it comes to rainwater collection?

Here are some tips that can help you decide where to begin. We originally discussed this in a post from 2014:

Whether you are designing your own rainwater catchment system or having one designed by a professional, success of your rainwater catchment system design is dependent on some key factors.

What do I want to accomplish with my design of a rainwater catchment system?

Irrigation, toilet and or laundry facility, supplementary to well water or city water, whole house usage, and sole source are the main purpose of designs.

How much rainwater can I collect from my roof? Will it be enough to supply my needs?

One inch of rainfall per 1,000 square feet of roof will yield approximately 623 gallons of water. Evaporation, wind, and spillage account for 15 – 20 % of loss. A 2,000 square foot roof with 36″ of annual rainfall may yield 44,856 gallons. With an efficiency of 85%, that equals 38,128 gallons.

One inch of rain is needed for the healthy growth of plants. This equates to .623 gallons per week for 1 square foot of planting, which can add up rather fast, so keeping your irrigation needs small and giving consideration to drought tolerant plants is recommended.

Toilet and laundry facilities account for 49% of household usage. Designing and building a system for this purpose alone can cut your water and sewer bill in half. New construction is the best time to implement this type of system however, retrofitting plumbing in an existing home can be accomplished.

Rainwater Catchment System Key FactorsIf the collection area is small or available space for storage is restricted, a supplementary system can be achieved with “slim line” style of cisterns or buried tanks. A small roof can still be effective in collection if used for a supplementary source to well water or city water.

Whole house usage, or potable water, can eliminate dependency on city water or well water, where you can still have city or well water as a back up during dry times. With the advanced filtration and UV disinfection offered today, safe, reliable drinking water for whole house usage will exceed the quality of most well and city water.

Now that you are considering what usage of collected rainfall would best suit your needs, we will discuss sizing, configuration, implementation, and maintenance of a designed rainwater catchment system in upcoming posts.

When you are ready to begin, RainBank will come to your site, discuss your needs and prepare a feasibility study – customized to your usage. There is a fee for this, which would be discounted from the cost when you contract with us to design or build your system. Use the form below to request a quote.

Rainwater Catchment, Water Tanks

Considerations for Underground Water Storage Tanks

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Xerxes underground tanksRainBank is experiencing increased interest in underground storage for our Seattle customers, requiring special considerations for underground water storage tanks.

Aesthetics and available space are the most common reasons from these customers. Many are building larger homes on small lots that once had a 1,200 square foot home with a front and back yard. New construction is trending towards a larger footprint, leaving less room for water storage tanks. Slimline tanks allow for less visual impact, but are restrictive on volume. Other residents are remodeling older existing homes that still have yard space available – and are looking for greater amounts of storage.  Below grade storage can be the answer, leaving a yard area that can accept landscaping right over the top of the water tanks.

Here are some things to consider with underground storage.

  • First and foremost – costs. Below grade storage will require excavation and. most likely, exporting much of that soil, which would have to be loaded and trucked off site.
  • Drainage needs to taken in account, with the new City of Seattle stormwater rules preferring infiltration for overflow. Where infiltration is not feasible, connection to the city storm system can be implemented for overflow as long as caution is taken to prevent sewer gases  or back flow from entering the tank.
  • Water tanks need to be properly vented and have a riser to access the tank for periodic cleaning and pump service. The installer must be sure that plumbing will not be compromised with slight settling or shifting of the tank.
  • Below grade tanks tend to be more expensive to meet engineering requirements of underground tanks, and once installed, are considered a confined space and caution must be taken if access is necessary. 

Underground-Tank-Construction3-1038x576For those who understand the considerations of underground storage, you have the luxury of landscaping that is free of visual impact and have different available options in tank sizes, styles, and materials. Tanks can be single or multiple, plastic or fiberglass. Cement tanks can be used for non potable use or lined with a NSF certificate for drinking water. 

Infrastructure, Sustainability

Rainwater Collection Can Cut Demands on Urban Water Supplies

Space_Needle_Mount_Ranier_Seattle_Washington_USAUrban growth, especially as seen in Seattle, can actually help cut demands on city water supplies. Still valid today, we wrote about this in July 2014 under the title Rainwater Collection Reduces Dependence on City Water in Seattle. Read more below:

As anyone who lives in Seattle can see, there is a massive amount of rental construction happening. With the growth of the South End of Lake Union and the Ballard area, over 23,000 units are expected to be added in the next few years.

A cultural shift in water conservation with simple technology can reduce the amounts of water usage through more effective water management practices. While the “Green Storm Water Infrastructure” or GSI mandates that runoff from impervious surfaces is to be infiltrated on site, other innovative and effective technologies are crucial in reducing the need for upgrading and expansion of sewer and centralized water systems.

Think of the reduction of the amounts of water coming off our roofs into stormwater if we diverted that water to usage such as toilet flushing and laundry facility. This practice could cut runoff by as much as 50% in high density housing complexes, while saving hundreds of thousands of dollars that would be used to meet the demand.

Bio swells and rain gardens do very little for infiltration during the rainy periods when the ground is already saturated. Rainwater collection used for toilet and laundry facility could be using that water during those months rather than having it overflow, and it would reduce the run off during those periods. The end product would be reduction of stormwater runoff, less dependence on city water and its infrastructure, cost savings to the building owner and tenants, better use of our natural resource, while reducing pollutants in our waterways.

Learn more about rainwater collection and whether it is a good fit for your home or commercial project. Use the form below to request a quote for a feasibility study.