Inventory, Monitoring, Research Catalog
4/15/13
1. Topic
Groundwater Recharge Quantities and Characteristics
2. Background
The surface and groundwater resources within the summit region are the result of inputs coming
from rainfall recharge and snow melt. As of the present time, there has been no comprehensive
attempt to quantify the volumes of recharge entering the summit groundwater system from these
sources. However, accomplishing this task presents many challenges: the distribution of rainfall
and snowfall over the summit is not uniform and is subject to surface contours and to structures
occupying the summit; some, unknown, fraction of the recharge may be associated with fog/cloud
drip; an unknown fraction of the rainfall and snowfall/snowmelt will be lost to evaporation and to
sublimation processes in the very dry environment at the summit. Furthermore, annual variability
and likely ongoing climate change will likely affect the recharge volume and possibly the recharge
distribution over the summit region.
3. Purpose
Quantify the volumes of rainfall/snowfall/snowmelt recharge that is entering the summit
groundwater system.
4. Research Objectives
Determine the volumes of net recharge entering the groundwater system within the Mauna Kea
summit. Begin development of a model for estimating the net recharge that is derived from rainfall
events of given rates and accumulations; develop similar models for fogdrip/cloud interception, and
for snowfall and snowmelt under varying temperature and humidity conditions.
5. Management Applications
Potential uses of Determining Groundwater Recharge Quantities and Characteristics could: enable
management authority to distinguish between natural and anthropogenic processes that may affect
surface water recharge and surface water quality in the summit region, develop effective policies
and mitigation strategies to minimize the impacts of current and future uses of the summit region
on surface water quantity and quality, and assess the impacts of changes in astronomy
infrastructure and surface contours on the recharge rates occurring in the summit region.
6. Comprehensive Management Plan (and Sub-Plans) Applicability
a. Priority –to be completed
b. NRMP Source – Section 2.1-39, 4.1-32, 4.1-34
7. Desired Outcomes
 Technical report describing the relative importance of the various natural recharge sources
in the summit region with an analysis of how changes in summit infrastructure may impact
those rates.
Prepared by: D. Thomas

A simple recharge model to estimate changes in recharge based on: rainfall rates and
intensities; snowfall and subsequent temperature and solar insolation data; and durations
of fog and cloud intercept conditions.
Prepared by: D. Thomas