Tag Archives: feasibility study

Rainwater Catchment

Key Factors In Planning a Rainwater System

Water. We simply can’t live without it. Safety, cost and convenience are some key factors to consider when planning a rainwater system for commercial or residential use. Will the water be used for irrigation? Toilet or laundry facilities? Or, will you and your family want to drink it?

Here are some key factors to help you decide where to begin designing your system. 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.

If 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 feasibility study.

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.

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.