Increase Fresh Water Capacity
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.
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.
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%).
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.
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
Learn More and Make a Difference
What You Can Do
- Whenever you see water being wasted (a broken water pipe, a malfunctioning irrigation sprinkler, a faucet left running, or something similar) please contact the Board of Water Supply’s Water Waste Hotline at 748-5041 or firstname.lastname@example.org
- 100 different ways to conserve water- http://wateruseitwisely.com/100-ways-to-conserve/
- Learn more about how Hawai‘i can collectively take action on increasing our fresh water security - http://www.hawaiicommunityfoundation.org/file/cat/Fresh_Water_Blueprint_FINAL_062215_small.pdf
- Learn more about changes in land use such as pavement and development visit - https://coast.noaa.gov/ccapatlas
- Learn more the about the Hydrologic Cycle in the Hawaiian islands - http://www.boardofwatersupply.com/water-resources/the-water-cycle
- Calculate your water footprint! - http://www.watercalculator.org/
- Visit the Commission on Water Resource Management’s website - http://dlnr.hawaii.gov/cwrm/
- Review the information available on the Hawaii’s Department of Health Clean Water page - http://health.hawaii.gov/water/
- USGS Water Data for Hawai‘i - http://waterdata.usgs.gov/hi/nwis/nwis
- “Hawaii First Water”, news and research on water issues in Hawaii - http://hawaiifirstwater.org/