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Protect Your Rainwater System During a Freeze

After living and working through The Freeze of February 2021, we want to provide our fellow harvesters with advice about how to best protect your rainwater system during a hard freeze. We recommend downloading the guide before the threat of a freeze so you can familiarize yourself with your system, specific valve locations, etc.

If you have a property you will not be staying at during the winter months, we recommend following our instructions for “Decommissioning a Rainwater System” until your return (included in the downloadable guide).


Our service team offers winterization service appointments. Contact us if you are interested in having our rainwater techs come out to inspect the system, ensure you are ready for colder weather or if you’d like assistance in decommissioning a rainwater system for a property you may not be returning to until spring.

Please note: While these recommendations are intended to help you protect your rainwater system during a freeze and minimize costly repairs, Harvest Rain cannot make any guarantees against system failure(s) during extreme weather.


Harvest Rain Freeze Guide


5 Steps to Protect Rainwater from Freeze


  • Small diameter = anything 2” or under. Typically these are pressurized pipes coming from your tank and/or the suction pipe to the pump if your pump is outside of the tank.
  • Wrap extra insulation around the main valve at the tank as this point is especially vulnerable during a deep freeze.


Keep the drain valve OPEN until the threat of freeze has passed and everything has completely thawed out (this may be several days after temperatures have begun to rise).



Find the lowest, furthest faucet from the disinfection station and open at a very slow drip. Depending on the severity of freeze,  you may need to drip multiple faucets to ensure water is continuously flowing through house plumbing. You may consider dripping a bathtub faucet and retaining the water in case of an extended power outage.


  • If any of your components (pump, disinfection system) are not in fully conditioned areas (ie non-insulated well house or exterior wall), consider running a heater, heat lamp, or wrapping in heat tape. You will also want to open faucets at a higher flow than a drip.
  • If you have a submersible pump, it will be protected by the water in the tank.


Extreme weather events are often accompanied by rolling blackouts or full power loss. To protect your UV light kit, ensure the unit is plugged into a surge-protected outlet.


and it is unlikely it will come back within 30 minutes and temperatures are below freezing: immediately follow the included instructions for “How to Decommission A Rainwater System” included in our full Freeze Protection Guide.

You can contact the Harvest Rain Service team by giving us a ring at 512-645-2955 OR by filling in the form below.


Rainwater Irrigation System: A Guide to Planning

Are you thinking about harvesting rain to use for your garden or landscaping? Read on for our Guide to Planning a Rainwater Irrigation System.

Rainwater is especially well-suited for irrigating raised beds, drip irrigation, trees, and small lawns. Not only will your water bill benefit, but plants love the soft, untreated water and reward you with bigger blooms, tastier fruits, and veggies than watering with well or city water.

Irrigation systems come in all sizes, from smaller barrels to massive, commercial-grade tanks. Harvest Rain starts our installations at 1,000 gallons and scales up from there, depending on the area of your roof used for collection and how you’ll use the collected water. 

When designing a rainwater irrigation system, we consider a few variables to ensure the final product is sized correctly and lives up to expectations, including:

  1. How much water do you use for irrigating? 
  2. How much water can you collect? 
  3. What will you be irrigating?
  4. Do you have a good spot for the right-sized tank?


We have several methods to help estimate how much water you are currently using or will use in the future.

If you are on city water:

1) Call your utility company…

Your water company should be able to provide your property’s historical usage. You can tease out your irrigation numbers from this data by comparing months you water to months you don’t. 

Example using historical water bills:

  • December 2020, no watering: 4,000 gallons
  • July 2021: 10,000 gallons
  • Estimate of Gallons Used for Irrigation in July: 6,000 gallons

2) Alternatively, check your water meter

Take a look at your meter directly before running your irrigation, noting the reading. Check the meter again after your irrigation cycle is complete. The difference is how many gallons you’ve used in a single cycle.

3) If you have a sprinkler system…

Your sprinkler system may have ‘GPM’ listed per Spray Head Flow at the controller unit, indicating how many gallons of water are used per minute either by zone or actual spray head. If so, you can do some quick math to estimate your irrigation usage.


  • Zone 1 – 2: 2 GPM / each
  • Zones 3 – 5: 8 GPM/each
  • Zones 6 – 10: 6 GPM /each
  • Total = 58 gallons of water/minute

Your water usage for (1) 20-minute cycle of irrigation using all zones= 1,160 gallons. If you are running your sprinklers 2x week = 2,320 gallons/week or 9,280 gallons/month.

If you are in the process of building a new home…

If you are working with a landscaper, you can request a projected water usage plan for their proposed design. This plan will outline how much water your landscaper anticipates you will need on a weekly, monthly, or yearly basis to establish new plants/grass as well as projected numbers for maintaining them.

On a well and unsure of how much water you use? 

Many of our customers have more than one water source on their property and are looking to augment their well usage with rainwater. But it can be challenging to know exactly how much water you’re using without a meter. We can use some rough estimates to help get you closer to your number:

Generally speaking, most Texas lawns need 1 to 1.5″ of water per week during the growing season. Let’s take two examples to explore what that means in gallons.

  • Example 1: A typical American backyard on a quarter acre property is about 8,500 square feet. Each 1,000 sq. ft. of lawn requires 624 gallons of water to receive 1″.
  • If your yard is 8,500 sq. ft = 5,322 gallons of water used to get 1″ of water into the lawn (often split up between multiple watering cycles/week).
  • Example 2: If you are looking at a more significant property and determining water usage, one acre = 43,560 sq. ft. 
  • Irrigating one acre of grass with 1″ of water = 27,137 gallons of water/cycle. 

A note about grass:

Using the math above, if you have a large lawn, it can be difficult to capture enough to rely on harvested rainwater alone for your irrigating needs. However, if you have considerable roof space and are open to a bigger storage tank, then one of our designs can likely meet your needs.


Once we have a solid working number of how much water we need, we start to look at the square footage of your roof and how much of the roof we will need to utilize. It’s not always necessary to maximize your roof’s capacity. For example, if you are simply irrigating a small veggie garden or flower beds, a 1,000-gallon tank may suffice. In that instance, we would try to identify a nice straight run of gutter from a portion of your roof that will easily fill the tank. 

Conversely, if we are looking to meet large irrigation demands, we will likely want to collect as much water as we can. This means we will design a system that captures rain from the entirety of your roof.


Our goal is typically to provide for 8-12 irrigation cycles with your rainwater catchment system. Depending on your irrigating patterns, this could be anywhere from 1-2 months’ worth of water.

If we have determined you use approximately 1,740 gallons per irrigation cycle, we’d like to aim for 14,000-20,000 gallons of stored water. 

Once we have established these working numbers, our system designers will work with you to select the final tank size. The final variable we’ll want to nail down is the actual spot for tank. Below are several common rainwater irrigation tank dimensions. However, tanks come in many more capacities. 

Common Irrigation Rainwater Sizes


We always want to provide our customers with a rainwater irrigation system that meets their expectations and clearly identifying how much water you need and how much water you can collect at the onset allows us to do just that. 


Go Native! With any new landscaping, you will initially use more water to establish plants and trees. However, when you opt for native plants and grasses, after 1-2 years, you can back off on supplemental irrigating and let nature take the reins. 

Additional Resources:

Texas AgriLife Extension is an excellent resource for landscape planning. They provide comprehensive lists of trees, shrubs, perennials, ornamental/prairie grasses, and more to help you select plants that tend to be drought-tolerant and require little to no fertilizers (both of which contribute to healthy rivers, lakes, and aquifers – something we really get behind!) 

Find the full ‘Native & Adapted Landscape Plants Guide’ PDF for the City of Austin and surrounding areas here.


Interested in getting more information about a rainwater system? Use the form below to contact our team today!

Additional Information

Maintaining a Rainwater Harvesting System

Curious what type of maintenance is required for a rainwater harvesting system? For the purposes of this article, we are discussing maintaining potable systems (i.e., rainwater systems that provide households with drinking water). When you live on rainwater, you are essentially maintaining your own utility, and you’ll want to ensure it provides the highest quality of water for you and your family.

Read below as we break down rainwater system maintenance. If you have an irrigation rainwater system, scroll to the bottom for our best nonpotable maintenance tips. 

If you are interested in scheduling a service maintenance appointment with our team, contact us here.


We’re going to start at the beginning of a rainwater catchment system – the roof and gutters and move down the conveyance line to the tank and finally your disinfection station.

2-4x/year (more frequently if you have overhanging trees) 

We always recommend snap-in leaf guards for gutters (not micromesh) when designing a new system or upgrading an older one. These screens act as the first step of pre-filtration for your collected rainwater, keeping most leaf, tree, and animal material (birds, squirrels, nests, etc.) from entering your storage tank.

You’ll want to wipe off these leaf guards and ensure both roof and gutters are free of excess debris. Fine dust particulates, etc., do not need to be entirely removed from the roof as your sediment filter will handle these.

2-4x / year

With all Harvest Rain potable installations, we include a first-flush to reduce the amount of sediment that ends up in your storage tank. Typically, these first flushes are a run of pipe that ends with a screen.

You’ll want to remove this small screen and rinse. We recommend cleaning the first flush screen on the same day(s) you change your filters and checking after significant weather events.

Your system may utilize an eliminator tank instead of a first-flush. If that’s the case, you’ll need to check that the eliminator automatically drains when full or periodically manually drain to ensure flush capacity during the next rain.

TIP: if your rainwater system does not have a first-flush or an eliminator tank, we invite you to schedule a service call to discuss an upgrade.

2-4x / year

All potable rainwater tanks should have a leaf basket/strainer where the inlet pipe meets the tank. There should also be a removable coupling or some way to detach the last PVC fitting/pipe that enters into the tank. Remove this fitting, then the leaf basket, wipe out any debris, rinse with water, and re-install.

Rainwater Tank and Leaf Basket Location

NOTE: Cleaning of the interior of a tank is typically only necessary every 15-20 years to help remove any accumulated sediment. 

When designing a system for a property with many oaks or overhanging trees in general, we first recommend trimming back tree limbs to prevent excess debris on the roof. Other times, we may also recommend a recirculation system to help negate pollen build-up (which can turn your water a light green – not harmful, but unsightly for sure!)

Give us a ring if you think your tank may need cleaning – we’re happy to direct you to some great resources.


The disinfection station is the most essential component of your potable rainwater system. Here, your stored rainwater runs through a sediment filter, a carbon filter, and finally, a UV lamp. If your system does not contain all three steps, we do not consider it a complete disinfection station.

Rainwater Disinfection System
Viqua E4 Ultraviolet Disinfection System

Frequency-based on size + demand 

The sediment filter should be the first in the disinfection line. We use sediment filters rated @ 5 Microns (meaning they remove anything 5 microns or bigger such as sand, silt, rust.)

Depending on the size of your filter housings, usage level, and the number of occupants, we recommend changing sediment filters monthly or quarterly. Smaller filter systems (2.5″X10″) require monthly changes. Larger systems, such as the Viqua E4 picture above, typically only need to be changed quarterly.

Most Common Filter Sizes

Your system may be equipped with two of the same size filter housings (aka sumps) or two different, depending on the installer and date of installation. Sediment and carbon filters come in various sizes, but the three most common are: 2.5 x 10″; 2.5 x 10″, 4.5″ x 20″.

Most Common Filter Housings for Rainwater
Unsure of what size filter your system uses? Contact us – we’re happy to help identify components. 

TIP: If you notice a reduction in water pressure, your sediment filter is the first place to check. When this filter is at the end of its lifespan, it will slow down the water coming into your home. Depending on your home’s water demand, you may find that you need to change your sediment filter more frequently than our above recommendations. 


The second filter of your disinfection station is the carbon filter, used to condition the water, improving taste and odor. We use a 10-micron nominal carbon filter on our systems. 

Like the sediment filters, how often you change the carbon filters depends on the filter size and demand. We typically recommend systems of 2.5 – 4.5×10 be changed quarterly and larger 4.5×20″ carbon filters changed 2x a year. 

This excellent chart from illustrates micron sizes and how they relate to the particles we’re removing.


Your ultraviolet light is the most critical part of your filtration system. Not only does it antibacterialize your water, but it also provides a potable supply without the use of chemicals like chlorine. 

These UV bulbs are typically rated for 10,000 hours and we recommend changing them annually. Although the bulb may continue to shine, the intensity of the light output will gradually decrease, as will its ability to disinfect your water. Read more about why we use UV light to disinfect rainwater here.

After you have completed the steps above, you have completed the maintenance of your rainwater harvesting system! 

Many of our customers enjoy being intimately familiar with their rainwater and opt to maintain their own systems. We sell filters and UV bulbs at our Dripping Springs location. 


Harvest Rain offers annual service agreements, even on systems we did not originally install. During a service maintenance appointment, our tech will complete the leaf basket cleaning, filter, and UV changes (when needed), as well as visual inspections of the gutters, downspouts, tank, pad, pump, and pressure tank. Contact our friendly service team below to schedule.


Rainwater systems used solely for irrigation water (i.e., nonpotable) do not employ as extensive a filtration system as potable rainwater collections; hence their upkeep is less involved. However, regularly checking the gutters, leaf guards, and leaf basket at the tank will help protect your irrigation system’s longevity. 


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