Hokuli'a

Hokuli'a Resort is a residential/resort development located on the slopes of the island of Hawai?i immediately below the town of Kealakekua, approximately two miles north of Cook's Monument at Kealakekua Bay.

During the construction phase of the project in September and November 2000, after short periods of locally-heavy rainfall, sediment stockpiled for golf course construction was observed running off into nearshore waters, resulting in a visible plume of turbid waters extending along the coastline immediately off the development site. Shortly after the September rainfall event, a Temporary Restraining Order halting all construction activities was granted.  Subsequently, a Stipulated Permanent Injunction was issued. Pursuant to the conditions of the Stipulated Permanent Injunction in the above civil action, the Third Circuit Court appointed Dr. David A. Ziemann of Oceanic Institute as Water Monitor for the above action.

The objective of the Hokuli'a Monitoring Plan was to make observations of water quality and marine benthic communities at locations and frequencies that provide answers to the following questions:

  • What are the current water quality and benthic community conditions at the Hokuli'a site?
  • Do water quality conditions in the coastal waters off the Hokuli'a site comply with applicable state water quality standards?
  • If coastal waters off the Hokuli?a site are not in compliance, to what extent are the construction activities at the Hokuli?a site contributing to these conditions?
  • Is construction at the site having a short-term, localized impact on water quality due to runoff or other discharges of sediment?
  • Is construction at the site having a longer-term, more regional impact on water quality due to surface discharges, discharge of nutrients into groundwater, changes in groundwater recharge or land use?
  • Is construction at the site having an impact on benthic communities due to runoff of sediment, discharge of nutrients into groundwater, changes in groundwater recharge or land use?
  • Has construction at the site had a lasting impact on water quality or benthic communities due to runoff of sediment,  discharge of nutrients into groundwater, changes in groundwater recharge or land use?

A series of water quality and marine biological community surveys were conducted in 2002-2004. These studies concluded that waters off the Hokuli'a resort are characterized by locally strong freshwater input through groundwater.

Freshwater input appears greatest at Nawaawaa Bay, and lower but still significant along the south border of the site. Evidence of freshwater can be observed as far as 500 meters offshore. Water clarity is high, with bottom features often visible at depths up to 30 meters (100 feet). Near the shoreline, water clarity is affected primarily by sediment re-suspended by wave action.

However, the finest sediment particles have been removed from the area by suspension and transport, so the remaining sediment is relatively coarse carbonate and lava sand that settles rapidly. Lava sand contributes most to the sediment along the south border of the site.

The survey data presented clearly demonstrate that there is addition of nitrate+nitrite-N to the groundwater under the Hokuli?a site, and as there are no other activities occurring between the upslope wells and the coastal wells and ponds and the ocean, activities at the Hokuli?a site must be the source of this additional nitrogen.

Estimates of the magnitude of the addition are variable and depend on which irrigation well best represents upslope groundwater. It is not possible to say with certainty which irrigation well best represents the conditions of groundwater flowing under the Hokuli?a site. The data from the two wells may give some idea of the variability of groundwater conditions along the South Kona coast.

The overall objective of the state water quality standards is to assure that human activities do not degrade coastal water quality or ecosystems and the capacity of the coastal waters to support appropriate uses. The discharge of additional nitrogen into coastal waters off the Hokuli?a site may not have immediate or significant impacts on water quality, except in the sense of further exceeding a set of numerical criteria based on approximations of general ambient conditions.

However, the discharge of nutrients into coastal waters can have significant impacts to benthic communities in the area, resulting in changes to community structure and composition of both sessile benthic organisms and associated fish communities. Such impacts can be cumulative and exacerbated by small increases in nutrient loading above that which is normal. Future marine biological monitoring should be expanded to cover shallow water communities where the input of nutrients in groundwater may have significant and visible effects.

The impact analysis concluded that corals off the Hokuli?a resort are generally healthy, with no evidence of mortality due to sediment loading or the presence of toxic materials. Corals in shallow waters are highly impacted by wave action during heavy surf.  Surveys observed broad swaths of broken corals, primarily Porites compressa, typical of the storm damage seen along the entire Kona coast.

The impact studies found no evidence of large changes in the fish community off Hokuli?a during the period of resort development. Community structure, overall abundance and mean biomass show no major differences between surveys conducted 1992, 1998 and surveys conducted by this study during 2003.