What is a Drought?
According to Merriam-Webster dictionary, a drought is: “a period of dryness especially when prolonged. Specifically: one that causes extensive damage to crops or prevents their successful growth”.
Reality is more complex. Droughts can occur from prolonged periods of dry, no rain weather, coupled with extreme temperatures. Droughts can also occur due to overconsumption of water that exceeds the water supply from rain and snow. This is why we mention Microsoft’s initiative at the end of this blog in our “spotlight” section.
The outcomes of a drought are much broader than damage to crops as the dictionary tells us. Unlike storms, earthquakes, and other natural disasters, the impacts from droughts go unnoticed many times for prolonged times until we realize their severe damage. Droughts increase fire hazard risks, affect water supply, wildlife, supply chains (of produce and cattle), the economy, and more. You can find more information about droughts, their consequences, and the magnitude of impact, at NOAA and USGS.
In this blog we cover:
- Are you living in a drought-impacted zone?
- Preventive measures from drought impacts
- Fire protection - roof, sidings, air quality
- Water conservation - greywater, water catchment
- Spotlight story
- Final thoughts
Do you live in a drought-affected zone?
The U.S Drought Monitor (USDM) is a team of people from various agencies or organizations that created a drought map in 1999 and are maintaining it to date. According to USDM, their map “uses five classifications: abnormally dry (D0), showing areas that may be going into or are coming out of the drought, and four levels of drought: moderate (D1), severe (D2), extreme (D3) and exceptional (D4).”
Below the map, you can find a weekly summary of the drought in different regions of the U.S.
What can you do to protect yourself?
In our blog about extreme temperatures, we discuss strategies to deal with rising temperatures such as insulation and energy management that are also relevant to droughts. In this blog, we focus on two main consequences of droughts: water shortages and wildfires, and how you can better protect your home and its occupants from these phenomena.
Droughts impact both surface water as well as groundwater supplies. Droughts reduce the amount of surface water (rivers, reservoirs, lakes) available to people and ecosystems. Weakening river stream flows hurt the natural wildlife in and around the river as well as dry the soil in its surroundings. When surface water is scarce, we tend to increase the amount and depths of groundwater drillings, in some cases contaminating them or simply drying them out.
The average American uses 140-170 gallons of water per day. 50% is used for landscaping. 27% is used for showers, 20% is used for toilets. We can all use at least 20% less water by a range of strategies, some are listed below.
Behavioral changes around your home
The U.S Environmental protection agency (EPA) provides an extensive list with tips on how to alter daily behavior at home to conserve water. The list includes preferable ways to wash food and dishes, optimal cleaning and laundry, and maintaining your garden or landscape.
Using Water Efficient products
The appliances that you choose in your home are significant for water conservation. Make sure you choose the right appliances that use less water. EPA’s WaterSense is a voluntary program that educates on water conservation importance and makes it easier to find and select water-efficient products, such as washing machines, dishwashers, faucets, and toilets.
This strategy helps reduce the use of potable water during extended periods of drought and was assessed as a preferred urban water recycling resilience strategy. Greywater refers to reclaimed water from laundry washers, showers, bathtubs, and restroom faucets. It excludes water from toilets, kitchen sinks, and dishwashers.
Greywater is collected by a separate drainage system. Greywater use reduces the amount of wastewater that needs to be treated and preserves potable water for other uses. A greywater system includes storage tanks, color-coded piping, filters, pumps, valves, and controls.
It is advised to check if local and state codes allow the recycling of greywater, methods, and permitted usage. In addition, please be advised recycling greywater is different from capturing rainwater (the following strategy we are discussing below), these are two separate strategies.
Water Catchment Systems
As with greywater recycling, the preservation of rainwater is strictly regulated by each state which has its own guidelines regarding rainwater catchment.
The objective of this strategy is to collect water for future use in the event of decreased precipitation, extended periods of drought, or extreme variation in water availability. Water catchment systems include cisterns, storage tanks, and ponds.
Tanks can be located above or below ground to store water. Storage should be sized based on projected precipitation volumes to maximize the volume of water that can be captured during a storm event. The stored water can be used for purposes such as outdoor irrigation, toilet flushing, and, with proper filtration and treatment, shower and potable uses.
It is important to note that some states limit the amount of rainwater collection, therefore, it is advised to check your local and state codes.
The long-term performance of both greywater and water catchment systems was analyzed in the urban water system concerning resilience, reliability, and cost of water supply/demand balance, and both strategies were recommended as efficient resilience measures.
In late September of 2020, Microsoft announced a “water positive” initiative that commits Microsoft to replenish more water than it consumes by 2030:
“By 2030 we will be water positive, meaning we will replenish more water than we use. We’ll do this by putting back more water in stressed basins than our global water consumption across all basins. The amount returned will be determined by how much water we use and how stressed the basin is.”
This adds to Microsoft’s other initiatives to become carbon negative and a zero-waste company. This is a great initiative by Microsoft and we plan on covering other corporate initiatives as well as tracking them over time.
Susceptibility to wildfires increases during drought periods. This is mainly due to longer periods with higher average temperatures leading to evaporation, resulting in hot and dry weather, leaving vast areas with dry plants and leaves that easily catch and maintain the fire. Dry leaves and pine needles are easily carried by the wind onto rooftops and sidings of the home.
There are several main strategies to protect your home from the damage of wildfires:
Class “A” Roofing System:
The objective of this strategy is to resist the intrusion of flames or embers from a vegetation fire into the building envelope.
The roof is the most vulnerable component of a house to wildfire, according to the Center for Fire Research and Outreach at the University of California, Berkeley. Standard tile roofs are particularly vulnerable to wildfire because wind-blown embers can enter attics through gaps in the tile system. Other entry points can be vents in the roof, eaves, and gables which should be properly covered to keep out small embers.
Class "A" roofing systems have the highest fire-resistance rating for roofing. Class "A" roofing systems are already required in many wildland-urban interface locations, or high-density urban developments. Adding Class "A" roofing to locations where it is not required by code may help protect a building from unexpected wildfires.
Class A roof materials include concrete roof tiles, asphalt fiberglass composition shingles, slate, and metal roofs. However, there are exceptions where other classes of materials such as aluminum, treated wood, and even some recycled rubber composite materials can meet a class A rating. For Class B materials to achieve a Class A rating, they need to be assembled in a certain way alongside additional materials, for example with their underlayment, sheathing, and flashing. This Class A rating is called “by assembly” or “assembly rating”.
The roof is such a critical and complex element of the house, it is important to add a couple of notes here:
- Unlike many other materials for other elements of the house, there is no clear “roof shingle” winner which is both “green” and “resilient” to all climate conditions (wind, precipitation, ice, and fire),
- The slope of the roof should be well-considered and designed to meet climate zones and extreme events as well as determine which materials will be used, as some materials behave differently in varying weather conditions and angles/slopes.
- Wood is probably the most eco-friendly material but requires additive chemicals to make it fire-retardant and achieve a class B, or even class A rating. However, those chemicals render it non-green.
- Green roofs have been a growing trend in urban, suburban, and rural areas. While both green and resilient against increasing temperatures and precipitation, green roofs need to be properly thought through in fire-prone zones. Some succulents perform better under fire, keeping moist soil as well as properly shielding the structure from the roof in case of a fire.
This strategy helps resist the intrusion of flames or embers from a vegetation fire into the building envelope. While siding is less often the point of home ignition in a wildfire than the roof, windows, or vents, it can be the weak point if these other components are particularly fire-safe or if an adjacent structure catches fire.
Exterior walls are susceptible to flames, conductive heat, and radiant heat from wildfires. These can, in combination, ignite combustible wall coverings. Increasing the fire resistance of exterior walls may prevent fire damage or the loss of the structure in the event of a wildfire.
Non-combustible options include fiber-cement siding, metal siding, three-coat stucco, and brick. Wood siding can be made “ignition-resistant” by treating it with an exterior fire-retardant chemical. As with the roof, entry points such as joints and vents should be properly designed to prevent the fire from reaching combustible parts within and inside the walls. Use fire-resistant sheathing and caulking for joints, and cover all existing vent openings with 1/8-inch fire-resistant wire mesh to prevent embers from penetrating inside the structure.
Wildfires create a thick layer of smoke that may linger for days and weeks forcing people to stay indoors. It is important to limit exposure to smoke indoors and there are relatively simple ways to achieve good levels of indoor air quality.
- Air Tightening - make sure there is no air leakage from and to the house. If the house is airtight, much of the smoke will stay outside. This means sealing gaps and cracks that smoke can enter through, usually around windows, doors, and the fireplace.
- Ventilation - a fully insulated and airtight house needs proper ventilation. There are three common options here: using fans, using the HVAC system fan in recirculation mode, and portable air purifiers. When using HVAC and/or air purifiers, it is highly recommended to use high-performance filters rated MERV13 (Minimum Efficiency Reporting Value) or a HEPA filter (if your HVAC / air purifier can use one) to battle the smallest particles.
There are additional fire protection strategies that we cover in a wildfire-specific blog, such as landscaping design, fireproof windows and doors, assurance of water supply, and a defensible space that can all save lives, especially in wildfire risk zones.
Prolonged, severe droughts are silent yet extreme climate events with dire outcomes. Droughts impact ecological ecosystems, economic sectors such as farming and agriculture, our well-being and homes. Risks surface either from broken supply chains (lack of produce and meat), scarce and poor quality water supply, and more noticeable risks such as frequent wildfires.
Mitigation and adaptation to droughts are big-ticket items that require nation and statewide collaboration and initiatives. On March 21, 2016, former President Obama signed a Presidential Memorandum directing federal agencies to build national capabilities for long-term drought resilience. The former President tasked the National Drought Resilience Partnership (NDRP) to work collaboratively to deliver on a Federal Action Plan including six goals and 27 associated actions to promote drought resilience nationwide.
However, you can still prepare your house to become a more resilient haven to the impacts of droughts by:
- Water: learn how to conserve water around your home by behavioral changes and choosing the right appliances, and follow state and local regulations regarding the recycling of greywater and catchment of rainwater.
- Fire: securing your roofs and sidings to be fire-resistant, air tightening your home in order to maintain better air quality during prolonged periods of poor air quality from wildfires.
Please share with us your own drought resilient strategies in and around your home.
KEEP COOL. BUILD RESILIENCE. EAMPACT.