|
Water Resources
<br />A warmer ocean and more acidic ocean stresses
<br />reef ecosystems from increased rainfall and runoff
<br />containing sewage, pesticides, and fertilizers.
<br />Rising sea surface temperature, also associated
<br />with increasing storm intensity, can cause similar
<br />damage. This impacts fish populations, the food
<br />web in marine ecosystems, and the communities
<br />who depend on them. Hawaii is impacted not only
<br />by global ocean acidification, but also coastal
<br />acidification resulting from localized land -based
<br />pollution, such as runoff and cesspools.16
<br />Further, wastewater and water line segments as
<br />well as on -site disposal systems are exposed to sea
<br />level rise. Saltwater intrusion from sea level rise into
<br />shallow coastal aquifers impacts potable water
<br />supplyfrom shallow coastal groundwater wells and
<br />underground infrastructure. Underground
<br />infrastructure may become corroded and
<br />contaminate freshwater and nearshore waters. The
<br />General Plan promotes One Water strategies in the
<br />Public Utilities section.
<br />Agriculture and Native Ecosystems
<br />Extended droughts can have cascading effects on
<br />native ecosystems, the economy, agriculture, and
<br />public health. Drought reduces stream flow, which
<br />decreases the water available to support stream
<br />and wetland habitats, agricultural irrigation,
<br />cultural practices, and aquifer recharge and
<br />freshwater supplies.17 Rain -fed fields and pastures
<br />are the most vulnerable to drought impacts in
<br />Hawaii. If droughts persist, irrigated areas can
<br />become vulnerable as well.18 Additionally, higher
<br />temperatures and drought degrade native forests
<br />through increasing tree mortality and accelerating
<br />grass invasion. Together, these factors can reduce
<br />the cover of high -quality forest and heighten
<br />vulnerability to fire impacts. Future drying with
<br />climate change will shift speak fire risk to higher
<br />elevations, endangering native forests mauka.
<br />Freshwater ecosystems are especially vulnerable
<br />to drought. Stream wildlife is adversely impacted
<br />by reductions in stream flow through the limited
<br />availability of freshwater habitat, loss of
<br />hydrological connectivity, and impaired water
<br />quality. Reduced surface water and groundwater
<br />inputs into nearshore environments may also have
<br />negative impacts on organisms in brackish and
<br />marine environments. Groundwater -dependent
<br />ecosystems, including fish ponds, anch.ialine
<br />pools, and coastal springs, are culturally and
<br />ecologically significant systems that are affected by
<br />drought and exacerbated by unsustainable water
<br />use. Longer and more frequent droughts increase
<br />the demand for potable and non -potable waterfor
<br />municipal and agricultural uses. Water supplyfrom
<br />County, private, and individual systems will be
<br />impacted by drought conditions and increased
<br />water use to support residents, agriculture,
<br />ranching, and tourism. Improving water
<br />infrastructure and conservation by increasing
<br />water storage capacity, reducing leakages from
<br />water systems, providing backup water systems,
<br />using stormwater to recharge groundwater
<br />aquifers, integrating groundwater -dependent
<br />ecosystem needs in sustainable water yield
<br />analysis, and conducting education and outreach
<br />activities are some of the key pre -drought
<br />management actions needed in a changing
<br />climate. The Collaborative Biocultural
<br />Stewardship section of the General Plan promotes
<br />balanced and resilient approach to managing land
<br />and resources.
<br />Critical Infrastructure
<br />Severe rainfall events, compounded by flooding
<br />and landslides, jeopardize critical infrastructure,
<br />communities, and coastal ecosystems. Runoff and
<br />flooding are some of the most disastrous impacts
<br />16 State of Hawai'i, Ocean Acidification Action Plan 2021 - 2031 (2021)
<br />https:Hdinr.hawaii.gov/dar/files/2021/09/State of Hawaii OA Action Plan.pdf
<br />17 COH, Multi -Hazard Mitigation Plan (2020) https•//www hawaiicouniy gov/departments/civil-defense/multi-hazard-mitigation-plan-2020
<br />18 Frazier, A.G.; Giardina, C.P.; Giambelluca, T.W.; Brewington, L.; Chen, Y.-L.; Chu, P.-S.; Berio Fortini, L.; Hall, D.; Helweg, D.A.; Keener, V.W.; et al.,
<br />(2022). A Century of Drought in Hawai'i: Geospatial Analysis and Synthesis across Hydrological, Ecological, and Socioeconomic Scales. Sustainability
<br />2022, 14, 12023. https://doi.org/l0.3390/su141912023
<br />3.0 Addressing Climate Change for Island -Wide Health I County of Hawaii General Plan 62
<br />
|