A cistern is a water storage tank, often underground, that collects rainwater or other sources for later use. Understanding its pros and cons helps homeowners decide if it’s a smart investment for saving water and money, offering significant environmental and financial benefits with careful planning and installation.
Ever wondered about where that extra water comes from when you need it most, or how some homes seem to use so much less water than others? It often comes down to smart water management, and a key player in that game is the cistern. For many homeowners, ‘cistern’ might sound like a complex plumbing term, but it’s actually quite straightforward: it’s a tank for storing water.
Whether you’re looking to be more eco-friendly, cut down on your utility bills, or ensure a water supply during drier months, a cistern could be a fantastic solution. But like any home improvement, it’s good to know the full picture. Don’t worry, we’ll break down exactly what a cistern is, explore its advantages, and look at any downsides, making it super clear if this is the right step for you.
Let’s dive in and make sense of cisterns, so you can make informed decisions for your home and your wallet!
What Exactly is a Cistern vs Pros And Cons?
At its heart, a cistern is simply a watertight container used to store water. Think of it as a specialized tank. While ‘cistern’ can broadly refer to any water tank, it most commonly refers to systems designed to capture and store rainwater or other non-potable water sources for later use. This water isn’t typically for drinking directly (unless treated extensively), but it’s perfect for many other household needs.
These tanks can be found above ground or, more commonly, buried underground. They can range in size from small residential units to massive municipal reservoirs. For homeowners, the primary goal is usually water conservation and reducing reliance on the main water supply.
How Cisterns Work: The Basic Idea
The concept is beautifully simple. Rainwater falling on your roof is collected by your gutters and downspouts. Instead of flowing straight into the storm drain, this water is diverted through pipes to the cistern. Often, the system includes a filter to remove leaves and debris before the water enters the tank. The cistern then holds this collected water until it’s needed.
When you need water for non-potable uses, like flushing toilets, watering your garden, or washing your car, a pump can draw water from the cistern and supply it to these specific outlets in your home. Some advanced systems can even integrate with your main water supply to top up the cistern or provide water when rainwater levels are low.
Cistern vs. Pros and Cons: Essential Savings
Deciding whether to install a cistern is a big step, and it’s wise to weigh the good against the not-so-good. This isn’t just about convenience; it’s about making an investment that can lead to significant savings and a more sustainable lifestyle.
We’ll look at the benefits that can lighten your bills and help the planet, as well as any potential challenges you might face. This way, you’ll have all the information you need to make the best choice for your home.
The Pros: Why a Cistern Is a Smart Home Addition
Installing a cistern can offer a surprisingly wide array of benefits. Many of these advantages translate directly into savings, both financial and environmental. Let’s explore the upsides:
1. Significant Water Bill Reduction
This is often the biggest draw for homeowners. By using stored rainwater for non-potable uses like flushing toilets, laundry, and garden irrigation, you drastically reduce your consumption of treated municipal water. Over time, this can lead to substantial savings on your monthly water bills. Imagine cutting your water expenses by 30-50% or even more, depending on rainfall and usage patterns!
2. Environmental Friendliness and Sustainability
Using rainwater is a powerful way to conserve a precious resource. It reduces the demand on local water treatment plants, which are energy-intensive. Furthermore, diverting rainwater can help reduce stormwater runoff, which can otherwise overwhelm drainage systems and carry pollutants into local waterways. It’s a direct way to contribute to a healthier environment.
3. Water Security and Independence
In areas prone to drought or water restrictions, a cistern provides a reliable backup water supply. You’re less dependent on municipal water pressure and availability, giving you peace of mind during dry spells. This independence can be crucial for maintaining your garden or even essential household functions during emergencies.
4. Reduced Stormwater Runoff
When heavy rain falls, unfiltered stormwater can carry pollutants like oil, trash, and fertilizers into rivers and lakes. By capturing rainwater in a cistern, you manage that flow, reducing the burden on storm drains and helping protect local water quality. You can learn more about stormwater management best practices from resources like the EPA’s National Stormwater Calculator, which can help estimate runoff.
5. Lower Energy Consumption for Water Pumping (Potentially)
If your cistern is gravity-fed or uses a low-energy pump, it can sometimes be more energy-efficient than pumping water from deep municipal sources. While pumps do use electricity, the overall energy footprint can be lower when you factor in the energy saved by not treating and transporting water from a distant plant.
6. Garden and Plant Health
Many gardeners swear by rainwater for their plants. Rainwater is naturally soft (low in mineral content) and free of chlorine and other chemicals found in tap water. This can lead to healthier, more vibrant plants and soil.
7. Increased Property Value
A well-installed and maintained rainwater harvesting system, including a cistern, can be a desirable feature for eco-conscious buyers, potentially increasing your home’s appeal and value.
The Cons: What to Consider Before Installing a Cistern
While the benefits are compelling, it’s crucial to be aware of the potential drawbacks and challenges associated with cisterns. Being prepared will help you avoid surprises and ensure a successful installation.
1. Initial Installation Cost
Setting up a cistern system involves significant upfront investment. This includes the cost of the tank itself, excavation (if burying), piping, filtration systems, and potentially a pump and a connection to your home’s plumbing. The total cost can range from a few thousand to tens of thousands of dollars, depending on the size and complexity.
2. Maintenance Requirements
Cisterns are not “set it and forget it” systems. They require regular maintenance to ensure water quality and system efficiency. This includes clearing gutters and downspouts, checking and cleaning filters, inspecting the tank for sediment buildup, and maintaining the pump. Neglecting maintenance can lead to water contamination or system failure.
3. Water Quality Concerns (Non-Potable Use)
Rainwater collected in a cistern is generally not safe for drinking, cooking, or bathing without advanced purification. It can pick up contaminants from the roof, air, and debris. While it’s fine for garden watering or toilet flushing, you’ll still need municipal water for potable uses unless you invest in a sophisticated, multi-stage filtration and disinfection system, which adds to the cost and complexity.
4. Space Requirements
Cisterns, even underground ones, require a considerable amount of space. Above-ground tanks can be visually intrusive, while underground tanks need sufficient space for excavation and installation, potentially impacting landscaping or existing structures. The size of the tank will depend on your water needs and local rainfall patterns.
5. Dependence on Rainfall
The amount of water you can collect is entirely dependent on how much it rains. In prolonged dry periods, your cistern may run dry, meaning you’ll have to rely entirely on your municipal water supply. This can be frustrating if you’ve invested heavily in the system expecting consistent water savings.
6. Potential for Mosquitoes and Pests (if not sealed properly)**
If the cistern is not properly sealed, it can become a breeding ground for mosquitoes and other pests. This is particularly true for above-ground tanks. Proper screening and secure lids are essential for pest control.
7. Local Regulations and Permits
Depending on your location, there may be specific building codes, regulations, or permits required for installing a rainwater harvesting system and cistern. It’s essential to research these requirements before you begin to avoid potential legal issues or having to redo the work.
Cistern vs. Pros & Cons Table
To help you visualize the trade-offs, here’s a table summarizing the key advantages and disadvantages:
| Category | Pros (Advantages) | Cons (Disadvantages) |
|---|---|---|
| Cost Savings | Reduces water bills significantly over time. | High initial installation cost. |
| Environmental Impact | Conserves municipal water, reduces stormwater runoff, sustainable. | Requires energy for pumps (if used). |
| Water Supply | Provides backup water supply, increases independence. | Supply is rainfall-dependent; may run dry. |
| Usage | Ideal for non-potable uses (gardening, toilets, laundry). | Rainwater generally not potable without extensive treatment. |
| Maintenance | Relatively simple for basic systems. | Requires regular cleaning, filter checks, and system inspections. |
| Space | Can be installed underground to save surface space. | Requires significant installation space (excavation for underground tanks). |
| Health & Safety | Provides water for essential non-potable uses. | Risk of contamination if not properly maintained or sealed; potential pest issues. |
| Regulations | May be encouraged by local incentives. | Can be subject to strict local regulations and permit requirements. |
Choosing the Right Cistern for Your Needs
When you decide that a cistern is the right move for you, the next step is selecting one that fits your property and your usage needs. Here are some key factors to consider:
1. Tank Material
Cisterns can be made from various materials, each with its own pros and cons:
-
- Polyethylene (Plastic): Lightweight, durable, cost-effective, and resistant to corrosion. Easy to install.
- Fiberglass: Strong, durable, and corrosion-resistant. Can be more expensive than plastic.
- Concrete: Very durable and long-lasting, excellent for underground installation, can help regulate water temperature. However, it’s heavy, more expensive, and can be susceptible to cracking if not installed properly.
A great resource for understanding tank options and their properties can often be found through local building supply stores or specialized water tank manufacturers.
- Metal (Steel, Stainless Steel): Extremely durable and can handle high pressure, but can be susceptible to rust (unless coated or stainless steel) and are generally more expensive.
2. Tank Size
This is crucial! The ideal size depends on several factors:
- Your Roof Area: A larger roof collects more water.
- Average Local Rainfall: How much water can you realistically expect to collect?
- Your Water Usage: How much water do you plan to use from the cistern for non-potable purposes?
- Storage Capacity Needed: Do you want to store water for a few dry days or several months?
A common recommendation is to have enough storage for your expected usage during a typical dry spell, multiplied by the average rain period you’re relying on.
3. Above Ground vs. Underground
- Above Ground: Easier and cheaper to install, accessible for maintenance. However, they take up yard space, can be unsightly, and may be more susceptible to temperature fluctuations and potential damage.
- Underground: Saves surface space, aesthetically pleasing, and provides better temperature stability. However, installation is more complex and costly due to excavation, and repairs or inspections can be more difficult.
4. Filtration and Pumping Systems
Consider what your system will need:
- Pre-filtration: Essential to remove leaves and debris before water enters the tank. Leaf guards on gutters and first-flush diverters are common.
- Post-filtration: If you’re using the water for more than just garden watering (e.g., laundry, toilet flushing), you’ll want finer filters to catch smaller particles.
- Pump: Most systems will require a pump to get water from the cistern to your home. Choose a reliable, efficient pump suitable for your needs. Submersible pumps are common for underground tanks.
Step-by-Step: Installing a Basic Cistern System (General Overview)
While professional installation is often recommended for safety and compliance, understanding the process can empower you. This is a simplified overview:
- Planning and Permitting:
- Assess your property for the best tank location (considering roof downspouts, drainage, and accessibility).
- Research local building codes and obtain necessary permits.
- Determine the appropriate tank size and type.
- Site Preparation:
- For underground tanks: Excavate the area, ensuring it’s level and properly prepared with a gravel base.
- For above-ground tanks: Prepare a stable, level base (e.g., concrete pad).
- Tank Installation:
- Carefully place the cistern in its prepared location.
- Connect inlet pipes from downspouts to the tank’s inlet. Ensure overflow pipes are directed safely away.
- Plumbing and Filtration:
- Install filtration units (e.g., leaf screens, sediment filters) on the inlet or outlet.
- Install the pump and connect it to the tank and your home’s designated water lines (e.g., for toilets, garden spigots). Consider a backflow prevention device.
- Testing and Commissioning:
- Test the system for leaks.
- Ensure the pump operates correctly and delivers water as expected.
- Check overflow mechanisms.
- Ongoing Maintenance:
- Establish a regular maintenance schedule for cleaning gutters, filters, and inspecting the tank.
Important Note: Working with plumbing, excavation, and electricity can be hazardous. For most homeowners, hiring a qualified professional installer is the safest and most reliable route. Companies specializing in rainwater harvesting can provide expert advice and ensure your system meets all standards.
Maintaining Your Cistern for Optimal Performance
A well-maintained cistern is an efficient cistern. Simple, regular upkeep ensures your water stays clean and your system runs smoothly. Here’s a basic maintenance checklist:
- Regularly Clear Gutters and Downspouts: Remove leaves, twigs, and debris at least twice a year, more often if you have many trees.
- Inspect and Clean Filters: Check sediment and leaf filters monthly or as needed, cleaning them to prevent blockages which reduce water flow and can damage the pump.
- Check the Tank Interior (Annually): Inspect for sediment buildup at the bottom. A thin layer of fine sediment is normal, but significant accumulation may require professional cleaning to prevent it from entering your plumbing.
- Examine the Pump: Listen for unusual noises and ensure it primes and pumps water effectively. Follow the manufacturer’s maintenance guidelines.
- Secure the Lid: Ensure the tank lid is tightly sealed to prevent pests, debris, and sunlight (which can encourage algae growth) from entering.
- Test Water Quality (Periodically): While not for drinking, regular testing can assure you there are no unaddressed contaminants if you’re using water for laundry or other sensitive uses. Consult local health departments for recommended testing protocols for non-potable water use.
Taking these small steps will help your cistern function optimally for years to come, maximizing your savings and water conservation efforts.
Frequently Asked Questions (FAQ)
Q1: Can I drink water from a cistern?
A: Generally, no. Rainwater collected in a cistern can contain contaminants from your roof and the air. It is suitable for non-potable uses like flushing toilets, watering gardens, and washing cars. Drinking water from a cistern requires a comprehensive multi-stage purification and sterilization system, which is often costly and complex.