Clean Water and Sanitation was identified as one of the 17 sustainable development goals (UN COP21) to transform our world. Public gardens are doing their part to adhere to this goal and inspire communities around them to do the same. As responsible environmental stewards, public gardens work to collect plants, protect plant genetic resources, and promote plant conservation. Adaptive and innovative water management is an integral part of responsible management of display gardens and plant collections. Public gardens have the opportunity to inspire future generations to think more sustainably about their own water use practices. The Water Quality & Consumption Attribute stresses the important role public gardens play in utilizing their water resources in the most sustainable ways possible. A wide range of best practices can set the standard for measurement, evaluation, design, construction, and implementation of strategies that minimize water consumption and promote surface and groundwater quality. Within this framework, public gardens can sustain a healthy and biodiverse ecosystem.
Goal 1: Recognize where water flows on your property and use your unique topography and ecology to reduce and delay runoff and promote infiltration of stormwater. If water is a scarce resource, capture, protect, and reuse stormwater.
Goal 2: Develop a clear and simple vision that governs the use of water for your garden. Ensure that all staff has a clear understanding of this vision and that it is apparent in your strategic plans, management plans, and operational norms.
Goal 3: Establish a set of best practices for collecting data and measuring your water usage and quality, and use the data to adjust future water management best practices.
Goal 4: Implement strategies that reduce water consumption and improve water quality on and off site.
Making the Case: Why Should We Care About Water Quality and Consumption?
ECOLOGICAL & SOCIAL IMPACT
The most recent California drought (2011-2017) has shown that we need to carefully monitor our groundwater usage and increase our retention of surface water. Making a deliberate effort to establish sustainable water management practices can improve a region’s economic, social, and environmental health. We must plan and implement changes that allow public gardens to withstand the impact of such droughts, but the land we manage must also serve to improve water quality and storage when and where rainfall is abundant. Reactive measures may provide a short term solution to drought and other water problems, but often adversely impact plant biodiversity, habitat, and wildlife needed to sustain ecosystems.
Reduced water usage at our public gardens can significantly reduce energy use. Water pumps and pressure systems consume a large amount of energy. By pumping less water out of the ground from aquifers and using alternative water sources, gardens can save electricity and decrease their reliance on fossil fuels and reduce the environmental impacts of power generation. Conserving water helps combat climate change locally, regionally, and nationally. Economic benefits of reduced water use make the case for broad adaptation of techniques for reducing water use in the communities served by our public gardens. Additionally, clean water in rivers, lakes, and streams fosters recreational activities and improved quality of life while nurturing animal and plant communities that need clean water to survive.
Use the Water Quality & Consumption Self-audit worksheet for the self-audit and use it to further track your planning decisions (see Develop and Implement a Plan of Action section below).
The following questions should be considered as part of an initial self-audit. Board members, water consultant professionals, and key leadership staff including those responsible for irrigation, operations and maintenance, and sustainability programs will ideally be part of this scoping process. The first step to a successful self-audit is determination of information and data that is needed for the self-audit.
IN SITU & EX SITU WATER CONSERVATION
- Is water conservation fundamental to your garden’s mission?
- Does your garden incorporate water conservation into existing plans, policies, and procedures (e.g. strategic planning, operational planning, or collections policies)?
- Has your garden installed new water infrastructure (e.g. irrigation systems, pipes) in the last 5 to 10 years on any part of your property? Has this increased water efficiency and decreased water consumption?
- Does your garden have educational panels, displays, or interpretative staff discussing water consumption and quality?
- Does your garden conserve water in a way that your visitors can emulate at home?
- Based on your garden’s current operations and goals, has your garden taken steps to reduce stormwater run-off and improve water quality?
- Does your garden test the water quality on your property at different areas including exit points and natural lands?
- Does your garden use or have a water conservation policy consistent with that of a local or nationally recognized organization/government entity?
- Does your garden have green infrastructure that recycles or retains water for use?
- Does your garden plan to rennovate, develop, or replace facilities, buildings, or infrastructure to improve water quality, flow, and storage?
- Has your garden explored the possibility of treating effluent water to recycle and use for maintenance and operational procedures (i.e. fountains, plant collections)?
- Does your garden select plants that require tempered water?
- Does your garden select drought tolerant plants?
- Has your garden identifed the plant collections that require the most and least watering?
- Does your garden have plant collections that are adjacent but require different amounts of water and are reliant on the same watering system?
- Does your gardens current irrigation system rely on old infrastructure that, if removed, would threaten historic and rare plant collections?
- Does your garden have maintenance practices in place that encourage water conservation?
- Does your garden regularly evaluate irrigation methods for all plant collections inside (greenhouses and conservatories) and outside?
Projects that build climate resilience and think big picture require broad support. To implement sustainable water initiatives, a highly engaged group of stakeholders representing the range of your garden’s mission is necessary. All the individuals and organizations that could be affected by inefficient water usage or poor water quality should be involved in providing input. Open discussion of the hazards and ramifications posed by polluted water sources and excessive water usage gives all stakeholders the opportunity to better understand and build a team with a shared vision to address the issue. Consider these questions when identifying stakeholders:
- Is your board and leadership staff supportive of water conservation initiatives that you want to tackle?
- Does your garden have a Sustainability Coordinator or Green Team that is focusing on water conservation issues? If not, has your garden considered creating such a position/team?
- Does your garden have any local or regional partnerships with external organizations or agencies?
- Do your stakeholders represent a balance of different interests, or are they skewed toward a particular ideal in terms of water consumption and quality?
- Has your garden reached out to local universities and colleges (environmental studies majors, etc.) and other research institutions for students, interns, and volunteers that would like to get involved/care about water conservation?
- Does your garden factor in water regulations that you need to comply with when making decisions?
- Has your garden considered colloborating with your utility company or other public-private partnerships to address water quality and usage?
- If water quality in your garden’s streams or water bodies is impacted by regional or local impacts, are there stakeholders that can influence changes off-site that will result in improved water quality for your garden?
Your stakeholder team must be informed about your baseline and the improvements that you wish to make to that baseline over time. They are often a key link to technical expertise, grant funding, and the general public. With their help, you have a much better chance at maximizing the return on dollars and effort spent, and can more easily publicize the positive role of your garden with regard to water resources.
After investigating and establishing baseline information on your water consumption and quality, the next step is to gather and manage data to inform future decisions. It’s important to create metrics that you can use to determine the success or failure of the measures you implement. Attainable benchmarks will help you chart your progress toward larger goals. Careful analysis of water use patterns and water quality will help pinpoint problems and give you a clear idea of work that needs to be done to resolve them.
- Does your garden use data collected (e.g. utillity bills, irrigation system technology, etc.) to inform decisions on water usage and quality in the future?
- Does your garden rely on a utility company for all water related data collection?
- Does your garden track domestic water use and cost?
- Has your garden designated staff members or a specific department for gathering all data and information concerning water use and quality? Doe this information get disseminated to the appropraite leadership staff?
- Does your garden know what percentage of water is consumed by different uses (e.g. landscape versus public facilities)?
- Does your garden install water-efficient plumbing fixtures in restrooms?
- Does your gardens kitchen/restaurant/café use water-efficient plumbing fixtures?
- Does your garden address the water efficiency of cooling tower operations?
- Does your garden know what percentage of stormwater from impervious surfaces is captured on-site?
- Does your garden have any flow meters or sub-meters that are collecting data on water usage?
- Does your garden evaluate various soil types and soil amendments including regularly tracking soil moisture data?
- Does your garden track the amount of fertilizer and mulch you use?
- Does your garden have a process for monitoring and determining when watering is needed (e.g. soil probe, soil sensors, evapotranspiration data)?
- Does your garden track how many irrigation heads and types you have, where they are all located, and what their spray radius is?
- Is the pressure on automated irrigation systems regulated to promote large droplet size to conserve water?
- Is irrigation timed for maximum benefit to the plants and greatest efficiency?
- Has your garden explored alternative sources of water for irrigation?
- Does your garden regularly check to ensure the water quality is suitable for the plants you need to water?
- Does your garden have stormwater retention features or bioretention features that are effective in improving water quality?
- Is there separate or combined infrastructure for potable and irrigation water?
These strategies have been identified by public garden professionals as tools for improving the way water can be recycled, measured, and used more efficiently. Determining which strategy is right is dependent on your garden's size, financial flexibility, regional regulations, climate, topography, and workforce. This list is intended to provide a small sample of ways gardens can implement plans to achieve more optimal water sustainability.
WATER FOCUSED PLANT COLLECTION STRATEGIES
- Pilot test new irrigation strategies in a few areas of your garden before investing in one system or strategy. There is no solution that works in all situations. Trialing a few strategies in different zones or areas of your garden is a way to evaluate and measure what is working best and what needs to be supplemented in the future as part of your strategic plan.
- Determine your most valued plant collections and the months of year where your water usage is highest. This may impact future changes in infrastructure and plant collection policies that address water conservation.
- Reach out to water focused non-profits (watershed organizations) and local governement agencies (EPA, state department of natural resources, environment & sustainability offices) to set up meetings or discussions on how your garden can collaborate with experienced professionals to reduce water consumption and improve water quality. These collaborations can be on-going and help your staff learn about creative, current, and more efficient water management strategies.
- Ensure that plant collection policies are aligned with landscape design and architecture goals. Plant collections that require the same amount of water should be grouped together when possible. Avoid putting plant collections that require different amounts of water adjacent to one another, especially if they are being watered by the same irrigation system or source. Divide plant collections into zones and determine which zones need the most and least water.
- Select drought tolerant and water efficient plant collections, especially if they are difficult to sustain in your region and climate.
- For small gardens and gardens on county owned property nearby cities, work with your district utility company. Focus on identifying your water source(s). Some of these companies will conduct a free audit and provide a report on your current irrigation system flaws, where water is coming from, and provide guidelines to increase your efficiency and repair damages. Descanso Gardens in Southern California used The Metropolitan Water District of Southern California to cut their water consumption by 65%.
STORMWATER AND INFRASTRUCTURE MANAGEMENT
Your garden should consider these strategies to prevent or delay stormwater runoff and conserve water:
- Bioretention features such as rain gardens, curb cuts/curb extension, stormwater planters/tree boxes, tree trenches, retention ponds/basins, and bioswales.
- Water storage features such as cisterns and rain barrels. Use a rain gauge to measure how much rainfall your garden is receiving to help determine how much to water your plants. Be sure to place your gauge out in the open so nothing blocks the rain from entering.
- Constructed Wetlands (a wetland area in a lower area depending on the topography of a garden can serve as a detention and ground water recharge basin). Stormwater wetlands generally are large, shallow, vegetated basins or regions designed to capture and treat stormwater runoff from nearby drainage areas, such as a parking lot or roadway. As stormwater runoff flows through the wetland, pollutants are removed when velocity is slowed and particles settle out of suspension. Nutrients are absorbed through plant roots.
- Green Roofs: A green roof is a roof of a building that is partially or completely covered with growing media and vegetation on top of a waterproof roof membrane. Rainwater falling on the rooftop is retained in the media and then used by the plants.
- Permeable Surfaces. Mandate that new paving be permeable, and explore opportunities for retrofitting or rebuilding existing impervious features to make them permeable. Examples include:
- Parking lots
- Mulching to stop erosion and evaporation and cool the soil.
- Rock bars, step pools, and other designs that can slow down water and direct water flow from walkways or pathways to areas where water may be needed.
- A ditch or channel with a variety of plants that cleanses water. Ditches or channels near parking lots or other paved surfaces can be used to remove silt and pollution from surface water runoff. Instead of channeling stormwater from the parking lot directly into a drainage pipe, a filter strip and bioswale can work together as a living drain to capture stormwater so that it leaves cleaner than when it entered. Pavement is graded to direct stormwater runoff from the parking lot and the road into the planted filter strip then into the bioswale where some water infiltrates the ground, replenishing groundwater supply.
EFFICIENT IRRIGATION SYSTEMS
- Automated irrigation systems that are fully integrated with evapotranspiration monitors.
- Drip irrigation for individual trees and shrubs. Sprinklers waste water by unnecessarily watering more than the plant and a lot is lost to evaporation. Instead, drip irrigation or a soaker hose is more precise and efficient, allowing less irrigation between plants and fewer weeds to grow.
- Effluent sump pumps.
- UgMO, Toro, Rainbird, TDS, or other soil moisture based systems that are zone specific. Each zone is tied to parameters that are set to a percent of soil moisture.
- Stream rotator heads (larger droplets for irrigation than a mist head).
- Ground sensors that measure temperature, soil moisture, and salinity. These sensors can link and feed data into a central database that can be checked online and/or via Bluetooth by staff members.
- Replace or put in new and more efficient pipelines that control and retain water flow and direction better.
PUBLIC FACILITIES & INTERNAL OPERATIONS
- Install flow meters and sub-meters throughout or in certain areas of your property. Meter by both building and landscape and compare costs and usage. If reliant on a utility bill, track water use by building and landscape, and work with your utility company to specify what information you need and want to make your garden more sustainable and to reach your water conservation goals.
- Invest in more efficient designs such as specialized glass for greenhouses and conservatories or cooling systems that can reduce dependence on water.
- Reduce reliance on water pumps for electricity.
- Install water-efficient plumbing fixtures in restrooms (automated sensors).
- Install water-efficient plumbing fixtures at restaurants/cafes (dishwashers).
- Drinking fountains: Install water filling stations on walkways.
- Manually water where required, ensure that your garden is watering at the most efficient times of day.
- Use demonstration gardens to provide trainings to visitors, showing them a wide range of ways to reduce their water consumption and increase water quality in their community. Ensure that these demonstrations are inclusive and include strategies that are affordable for all participants.
- Determine how your water usage and quality is currently being measured and how often (daily, weekly, monthly).
- Use Energy Star PortfolioManager to track water consumption, checking regularly: https://www.energystar.gov/buildings/facility-owners-and-managers/existing-buildings/use-portfolio-manager
- Determine staff members that are responsible for when and where watering needs to take place daily.
A comprehensive water audit examines groundwater wells, aquifer management, and pressure pump efficiencies in order to gain a holistic understanding of the overall system. Checking irrigation systems and tracking the flow of water is necessary to ensure water is being used efficiently and not being wasted.
WATER QUALITY EVALUATION
- Track how much insecticide and pesticide products you are using (See Materials Management Attribute). Ensure that these materials are stored properly so water contamination is unlikely.
- Consider developing nutrient management plans for greenhouse crops, turfgrass, and areas that require fertilization to limit potential for nutrient contamination of surface water and groundwater.
- Purchase fuels, lubricants, pesticides, and fertilizer in quantities that will be used within a reasonable time to avoid potential for environmental contamination.
- Develop and follow a rigorous inspection plan for underground storage tanks for fuels.
- If applicable, work with adjacent agricultural landowners and/or neighbors to ensure your combined stormwater runoff and chemical applications are not worsening your streams, rivers, or other bodies of water.
- Work with external sources or internal staff to conduct a water quality study on site and off site (nearby watersheds).
- Measure pH level regularly (assigning appropraite staff to do so).
- Evaluate how expansion of plant collections, new construction projects, and other additions impacts the directional flow of water through your property.
- Determine key sample points where you can repeatedly measure water quality (e.g. a drainage pipe that flows water into a retention pond).
- Plan development so streams have access to floodplains during heavy rainfall events to limit erosion and downstream flooding.
WATER CONSUMPTION ANALYSIS
- Determine and evaluate the effectiveness of your irrigation heads and their spray radius.
- Be aware of aquifer locations on your property and how much groundwater you are using. Execute a plan to monitor aquifer levels.
- Determine how many gallons of water are captured by rainwater harvesting and how that water is redistributed to areas of your garden. Design storage systems such as cisterns to maximize the probability that harvested stormwater can meet most irrigation needs.
- Monitor progress through phases to find a more efficient irrigation system.
- Track size of irrigated areas in acreage.
- Report on installed rainwater harvesting levels (retention ponds, cisterns, rain barrels, etc.)
- Evaluate soil moisture levels, checking weekly.
- Ensure that irrigation infrastructure is monitored and any issues such as leaks are reported and addressed in a timely manner. Operations and maintenance staff should determine a timeline for older infrastructure that may need to be replaced both in the short term and long term.
- Make clear who is in charge of monitoring water usage and disseminating that information to the appropriate staff members.
- Train staff that are in charge of evaluating and monitoring water quality and usage in any new irrigation or data collection procedures and methods that are more efficient.
- Be sure all responsibilities are communicated and outlined clearly such as regularly checking dams for erosion and pipes for leaks.
Whether a public garden has a designated Green Team or Coordinator in charge of water sustainability efforts, all staff members should be aware of what is being done to conserve water and improve water quality. Public gardens can indirectly impact the way visitors use their water on their own landscapes by the way they’ve designed their buildings and facilities or the way they’ve used their landscape to recycle water to plant collections. Educating the public on sustainable water usage should be targeted to share innovations with the people who are most likely to adopt them.
- Report water conservation achievements in garden publications, on garden website, and social media.
- Communicate via interpretive walks and educational programs how stormwater is reused or cleansed as it travels through your property and ways visitors can emulate these actions at home.
- Interpret your water conservation initiatives through displays, panels, and exhibits.
- Communicate future plans and goals for water conservation and water quality to the public, operations and maintenance staff, and other stakeholders.
- Publicize and communicate to visitors all facilities that were certified (LEED) or built with water efficieny in mind.
Generate an internal (curators/collections staff) and external report on what plant collections your visitors value the most and whether new irrigation systems might positively or negatively impact the long term health of these plant collections.
Brad Lancaster’s Rainwater Harvesting: Drylands and Beyond: https://www.harvestingrainwater.com/
Check our distance learning offerings on the Association website or regularly check this site for upcoming water management webinars: https://www.epa.gov/watersense/webinars
The Public Gardens Sustainability Index Working Group is made up of diverse field-wide professionals. Does your expertise lie within an Attribute area? Help us build content for Principles and Best Practices. Have success stories? Let us collect your Case Studies. Contact Tommy Rosenbluth: email@example.com
Brooklyn Botanic Garden
When you think of dieting, do you think of gardens? You should! The Brooklyn Botanic Garden (BBG) is going on a water diet! In an effort to reduce the garden’s environmental footprint, the BBG has elected to cut its Japanese Hill-and-Pond Garden’s water use, which uses 22 million gallons per year, by 95 percent. In response to global climate changeprediction models, which indicate increased drought for the Northeast, this $17.2 million effort is unfolding in stages and is expected to be complete in 2018.
The Japanese Hill-and-Pond Garden at the Brooklyn Botanic Garden (BBG) is one of the oldest and most visited Japanese-inspired gardens outside Japan. The garden features artificial hills contoured around a pond, a waterfall, and an island, along with carefully placed rocks. The pond along has typically required 22 million gallons of water each year, until now.
The BBG has set a phase-driven recirculation plan into motion in an effort to reduce the garden’s environmental footprint and respond to predicted climate change models for the Northeast United States. The first phase of the project, a water garden, will be open to the public in September 2016. The system’s advanced technology, which regulates filtration, recirculation and volume control, is powerful. However, the challenge will be implementing the system discreetly so as not to distract from the surrounding beauty. Eventually, the recirculation system will capture water throughout the entire botanic garden and be redirected to the Japanese Hill-and-Garden pond. For more information on this case study, click here.
Phipps Conservatory and Botanical Gardens
Designed to be the greenest building in the world, the Center for Sustainable Landscapes (CSL) at Phipps Conservatory and Botanical Gardens generates all of its own energy and treats all storm and sanitary water captured on-site. The decision to implement the system came about early in the design process of the CSL project, because of the requirement for the project’s site boundary to not discharge any water to the city’s storm/sanitary systems. The lagoon supports Phipps’ mission on many fronts by creating program space, adding to sustainable landscape display gardens, and supporting storm water management infrastructure.
The project team assembled to design and implement the system included a civil engineer, contractor, pond consultant, landscape architect, and facility operators; however, Phipps horticultural and facility staff are responsible for regular maintenance and upkeep of the system.
Center for Sustainable Landscapes Photo: Denmarsh Photography
Rainwater is captured from display garden glass roofs and is sent into the lagoon, there it is filtered through natural wetland plants. Water is pumped through a series of skimmers to move water to fountains that help circulate the water and add oxygen to the system. The natural lagoon cleans the water and controls stormwater runoff surges. The lagoon is one element in the overall stormwater management systems on campus; it also helps clean water naturally before it is used for irrigation on our upper campus. It provides habitat and science education program space for staff. Also, it shows to the surrounding region how parks and fountains can provide stormwater management when green infrastructure is integrated into the design of our public spaces.
The Design Alliance Architects designed a net zero water diagram to articulate the system stages. Photo: The Design Alliance Architects
U.S. National Arboretum
The U.S. National Arboretum in Washington, DC, partnered with the District of Columbia
Department of Energy and Environment to restore Springhouse Run, a channelized, degraded stream on the property. A pond that was formerly separated from the stream has been modified to store stormwater to delay its movement down the stream, and the stream is now able to inundate its natural floodplain to maximize water infiltration and reduce erosion. Many different types of hydrological conditions have been designed into the project to provide ideal growing conditions for a wide array of native plants. The plants used to revegetate the site are grown from seeds collected from local populations and serve as a gene bank for regional flora that is threatened by development.