Increase Fresh Water Capacity

By 2030, increase fresh water capacity by 100 million gallons per day using a baseline capacity of January 1, 2016.

In 2013, Hawai‘i’s statewide water demand was 449 million gallons per day (mgd). Using this figure as the baseline, coupled with projections for population increase, it is estimated that 100 mgd of additional fresh water capacity* is needed in order to meet Hawai‘i’s future water demands without extracting more valuable groundwater resources or resorting to high cost alternatives such as desalination. To achieve this ambitious goal, key stakeholders across the public, private, and philanthropic sectors must work together on conservation, reuse, and recharge initiatives.

* Fresh water capacity refers to the amount of water available for consumption, and can be defined as the total decrease in water demand combined with the increase in water supply.

Figure 1: Conservation, Recharge, and Reuse goals for Hawaiʻi.

Freshwater capacity is a combination of conservation, recharge, and reuse data statewide, equivalent to approximately 13 million gallons per day (mgd) as of 2017. The most current data available for water conservation is 164 gallons per person per day, which needs to be reduced to 130 gallons per day per person to achieve Hawai‘i’s 2030 goal. Recharge data from U.S. Geological Survey (USGS) Volcanic Aquifers of Hawaiʻi report estimates an average of 45 mgd of direct recharge** from 2001-2010. Assuming this trend remains consistent, 45 mgd is the projected recharge value for 2017. Water Reuse is estimated at 134 mgd in 2016. Currently, there is no updated measure for 2017, so reuse remains at zero mgd. With each of these three values combined, total freshwater capacity is approximately 13 mgd.
Fresh water targets were produced in collaboration with the Fresh Water Council, an innovative collaboration between federal, state, county, nonprofit, academic,and private sector stakeholders with expertise in water issues. For more detailed information on the Council and targets refer to A Blueprint for Action.
**Direct recharge refers to the leakage from water mains and cesspools and seepage beneath land covers that are typically saturated, including taro, water bodies, and reservoirs.

CONSERVATION

164 GALLONS OF WATER PER DAY PER PERSON

Water conservation is the most efficient and cost effective way to manage the demand on Hawai‘i’s limited fresh groundwater resources. Conservation can be achieved through improving the efficiency of residential and agricultural water use. Since a quarter of all water pumped statewide is used for agriculture (see Figure 1), Hawaiʻi should focus on improving efficiency in agriculture water use by 15% by 2030.


Figure 1: Reported water use data in million gallons per day (mgd), by island and sector 2017 (Not all water use data was reported, reporting compliance = 48%).

Figures 2-5: A pie chart representing percent water used per county by sector, 2017 (Not all water use data was reported, reporting compliance = 48%).

RECHARGE

7.5% RISE IN PAVED PARADISE

Water recharge delivers rainfall and surface water back into aquifers. Over time, developed areas and pavement has changed the way water naturally recharges by preventing water from being absorbed back into the earth. From 2005 – 2011 there was approximately a 7.5% increase in development and paved areas statewide (NOAA C-CAP). In addition, changes in upland forest have reduced the amount of direct water recharge. Recharge can be improved through increasing upland forested protection (Visit Watershed) and increasing green infrastructure. Metrics to measure green infrastructure are still being defined and will be tracked as new green infrastructure projects are completed.

Figure 6: Impervious surfaces across Hawaii; Source: USGS The National Map (nationalmap.gov)

REUSE

16.4% OF WASTEWATER BEING REUSED

Approximately 120 million gallons of wastewater from treatment plants are discharged daily. To divert wastewater to other fresh water uses, Hawai‘i should: 1) Ensure that the right quality water is matched with the right and safe end use and 2) Eliminate barriers to recapture and reuse. The cost to treat and reuse recycled water can be as much as twice that to produce potable water. To reduce costs, strategically placed small-scale water filter plants can divert wastewater for non-potable applications, including irrigation for parks, golf courses, and local agriculture. To reach the reuse target, the freshwater council set the aspirational target of reaching 40% reuse by 2030. Currently 16.4% of Hawai‘i’s wastewater is reused statewide.

Figure 6: State of Hawai‘i Wastewater Reuse

Source: Department of Health, Wastewater Branch

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What You Can Do

More Information

SDG 6 - Clean Water and Sanitation
Ensure access to water and sanitation for all
SDG 12 - Responsible Consumption and Production
Ensure sustainable consumption and production patterns
SDG 14 - Life Below Water
Conserve and sustainably use the oceans, seas and marine resources
SDG 15 - Life on Land
Sustainably manage forests, combat desertification, halt and reverse land degradation, halt biodiversity loss
SDG 17 - Partnerships for the Goals
Revitalize the global partnership for sustainable development