Instream Flow Standard Assessment Report Island of Maui Hydrologic Unit 6006 Launiupoko January 2018 PR-2018-03 State of Hawaii Department of Land and Natural Resources Commission on Water Resource Management COVER Satallite image of Launiupoko Gulch with the Launiupoko Stream flowing into the Pacific Ocean, West Maui [Google Earth, 2008]. Note: This report is intended for both print and electronic dissemination and does not include diacritical marks in spelling of Hawaiian words, names, and place names due to problems associated with its use electronically. However, Commission staff has made attempts to include diacritical marks in direct quotations to preserve accuracy. Table of Contents 1.0 Introduction ......................................................................................................... 1 General Overview ................................................................................................................................... 1 Current Instream Flow Standard ........................................................................................................... 1 Instream Flow Standards ....................................................................................................................... 1 Interim Instream Flow Standard Process ............................................................................................. 2 Instream Flow Standard Assessment Report ...................................................................................... 3 Surface Water Hydrologic Units ............................................................................................................ 4 Surface Water Definitions ...................................................................................................................... 4 2.0 Unit Characteristics .......................................................................................... 11 Geology .................................................................................................................................................. 11 Soils ....................................................................................................................................................... 11 Rainfall ................................................................................................................................................... 12 Solar Radiation ..................................................................................................................................... 14 Evaporation ........................................................................................................................................... 14 Land Use ................................................................................................................................................ 15 Land Cover ............................................................................................................................................ 16 Flood ...................................................................................................................................................... 17 Drought .................................................................................................................................................. 18 3.0 Hydrology .......................................................................................................... 29 Streams in Hawaii ................................................................................................................................. 29 Ground Water ........................................................................................................................................ 29 Streamflow Characteristics ................................................................................................................. 31 Long-term trends in flow ...................................................................................................................... 32 4.0 Maintenance of Fish and Wildlife Habitat ....................................................... 37 Hawaii Stream Assessment ................................................................................................................. 38 5.0 Outdoor Recreational Activities ...................................................................... 40 6.0 Maintenance of Ecosystems ............................................................................ 43 7.0 Aesthetic Values ............................................................................................... 51 8.0 Navigation ......................................................................................................... 52 9.0 Instream Hydropower Generation ................................................................... 53 10.0 Maintenance of Water Quality ......................................................................... 54 11.0 Conveyance of Irrigation and Domestic Water Supplies .............................. 59 12.0 Protection of Traditional and Customary Hawaiian Rights ........................... 60 Taro Production .................................................................................................................................... 63 Fishponds .............................................................................................................................................. 65 Pre-European Contact Agriculture ..................................................................................................... 66 Hawaiian Home Lands .......................................................................................................................... 67 13.0 Noninstream Uses ............................................................................................ 70 Launiupoko Stream Diversion ............................................................................................................. 70 Modifications of Ditch Systems and Groundwater Recharge .......................................................... 74 i Utilization of Important Agricultural Lands ........................................................................................ 76 Diverted Water from Launiupoko Stream ........................................................................................... 79 Irrigation Needs of the Launiupoko Service Area ............................................................................. 79 14.0 Bibliography ...................................................................................................... 94 15.0 Appendices ..................................................................................................... 102 ii List of Figures Figure 1-1. Information to consider in setting measurable instream flow standards. ..................................................... 2 Figure 1-2. Simplified representation of the interim instream flow standard and permanent instream flow standard processes. Keys steps of the adopted interim IFS process are depicted in the left column by the boxes drawn with dotted lines. ...................................................................................... 3 Figure 1-3. Quickbird satellite imagery of the Launiupoko hydrologic unit and streams in southwest Maui, Hawaii. (Source: U.S. Geological Survey, 1996; State of Hawaii, Commission on Water Resource Management, 2015c; State of Hawaii, Division of Aquatic Resources, 2005)................................................................................................................................................................ 7 Figure 1-4. Elevation range of the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2004e; U.S. Geological Survey, 2001) ............................................................................................. 8 Figure 1-5. USGS topographic map of the Launiupoko hydrologic unit. (Source: State of Hawaii, Planning Department, 2004) ............................................................................................................................ 9 Figure 1-6. Major and minor roads for the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning 2015) ................................................................................................................................ 10 Figure 2-1. Orographic precipitation in the presence of mountains higher than 6,000 feet. ........................................ 13 Figure 2-2. Mean annual rainfall of the Launiupoko hydrologic unit. (Source: Giambelluca et al., 2013).............................................................................................................................................................. 20 Figure 2-3. Mean annual solar radiation of the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015c) ................................................................................................................. 21 Figure 2-4. Mean annual potential evapotranspiration (Penman-Monteith method) of the Launiupoko hydrologic unit. (Source: Giambelluca et al., 2014) ................................................................... 22 Figure 2-5. Generalized geology of the Launiupoko hydrologic unit. (Source: Sherrod et al., 2007).......................... 23 Figure 2-6. Soil classification of the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015m) ........................................................................................................................................... 24 Figure 2-7. State land use district boundaries of the Launiupoko hydrologic unit (Source: State of Hawaii, Office of Planning, 2015d). ................................................................................................................ 25 Figure 2-8. C-CAP land cover of the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015k). ....................................................................................................................................... 26 Figure 2-9. Hawaii GAP land cover classes of the Launiupoko hydrologic unit (Source: State of Hawaii, Office of Planning, 2015f). ................................................................................................................. 27 Figure 2-10. FEMA flood zone regions in the Launiupoko hydrologic unit (Source: Federal Emergency Management Agency, 2014). ...................................................................................................... 28 Figure 3-1. Diagram illustrating the ground water system west of Keanae Valley, northeast Maui, Hawaii. Arrows indicate general direction of ground water flow (Source: Gingerich, 1999b). ........................................................................................................................................................... 31 Figure 3-2. Ditches, diversions and gaging stations in the Launiupoko hydrologic unit (Source: State of Hawaii, Commission on Water Resource Management, 2015a). ..................................................... 33 Figure 3-3. Seepage run results and median flow from partial record gaging stations of the Launiupoko hydrologic unit (Source: State of Hawaii, Commission on Water Resource Management, 2015a; Cheng, 2014). ............................................................................................................. 34 Figure 3-4. Aquifer system and well locations (with well numbers) of the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015d; State of Hawaii, Commission on Water Resource Management, 2015f) ........................................................................................................... 35 Figure 3-5. Cumulative departures of monthly mean flow from the mean of the monthly flows, Hawaii. This data is based on complete water years from 1913 through 2002. (Oki, 2004, Figure 4) ........................................................................................................................................................ 36 iii Figure 4-1. Elevational profile of a terminal-estuary stream on the Big Island of Hawaii (Hakalau Stream). (Source: McRae, 2007, adapted from Nishimoto and Kuamoo, 1991 [with permission]) ................................................................................................................................................... 37 Figure 5-1. Public hunting areas for game mammals in Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2002b) ............................................................................................................. 41 Figure 5-2. Recreational and aesthetic points of interest as well as coastal resources for Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 1999, 2002c; 2004a) ............................................................................................................................................................ 42 Figure 6-1. Simplified ecosystem illustrated in a Hawaiian stream. (Source: Ziegler, 2002, illustration by Keith Kruger). ........................................................................................................................... 43 Figure 6-2. Reserves and wetlands for the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2007b; 2015n) ................................................................................................................. 48 Figure 6-3. Distribution of critical habitat for plant, bird and snail species in the Launiupoko hydrologic unit. (Source: Scott et al., 1986; State of Hawaii, Office of Planning, 1996; 2004b) ............................................................................................................................................................ 49 Figure 6-4. Density of threatened and endangered plants in the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015h) ..................................................................................... 50 Figure 10-1. Water quality standards for the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015e; 2008). The classifications are general in nature and should be used in conjunction with Hawaii Administrative Rules, Chapter 11-54, Water Quality Standards. ..................................................................................................................................................... 58 Figure 12-1. Traditional ahupuaa boundaries in the vicinity of Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015j) ..................................................................................................... 68 Figure 12-2. Zones of intensive agriculture in the Launiupoko hydrologic unit pre-European contact. (Source: Ladefoged, 2009) .............................................................................................................. 69 Figure 13-1. All registered diversions and ditches identified in the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2004d; State of Hawaii, Commission on Water Resource Management, 2015g) .......................................................................................................... 73 Figure 13-2. Estimated recharge for six historical periods between 1926 and 2004, central and west Maui, Hawaii. (Source: Engott and Vana, 2007) .................................................................................... 75 Figure 13-3. Summary of estimated recharge, in million gallons per day, for various land-use and rainfall conditions in the Lihue Basin, Kauai, Hawaii. (Source: Izuka et al., 2005) ........................................ 75 Figure 13-4. Agricultural land use for the Launiupoko hydrologic unit based on the Agricultural Lands of Importance for the State of Hawaii (ALISH) classification systems. (Source: State of Hawaii, Office of Planning, 2015g) ................................................................................................... 77 Figure 13-5. Designated gricultural land use for the Launiupoko hydrologic unit based on the Agricultural Land Use Map (ALUM). (Source: State of Hawaii, Office of Planning, 2015h)............................ 78 Figure 13-6. Mean daily flow (million gallons per day, mgd) diverted by Pioneer Mill from Launiupoko Stream into Launiupoko Ditch calculated from monthly data from 1983-1987. (Source: Pioneer Mill Co Registration, DIV.955.6) ......................................................................................... 79 Figure 13-7. Mean daily flow (million gallons per day, mgd) diverted by Launiupoko Irrigation Co. from Launiupoko Stream to Launiupoko Ditch calculated from monthly data from 2009- 2016. (Source: Lea Tamayose, West Maui Land Co.) .................................................................................. 79 Figure 13-8 Percent of each TMK in the Launiupoko Irrigation Company service area in agriculture as determined using remote sensing. ............................................................................................................ 90 Figure 13-9. Percent of each TMK in the Launiupoko Irrigation Company service area in landscaping as determined using remote sensing. ........................................................................................ 91 Figure 13-10. Estimated water demand of each TMK in the Launiupoko Irrigation Company service area based on land cover (agriculture or landscaping) using remote sensing and modeled water demand for that land cover. ................................................................................................... 93 iv List of Tables Table 2-1. Area and percentage of surface geologic features for Launiupoko hydrologic unit. (Source: Sherrod et al, 2007) ........................................................................................................................ 11 Table 2-2. Area and percentage of soil types for the Launiupoko hydrologic unit. ...................................................... 12 Table 2-3. Fog drip to rainfall ratios for the windward slopes of Mauna Loa on the island of Hawaii and approximate contributions to the Launiupoko Hydrologic Unit based on an elevation range of 2000-4680 ft..................................................................................................................................... 14 Table 2-4. C-CAP land cover classes and area distribution in Launiupoko hydrologic unit. (Source: National Oceanographic and Atmospheric Agency, 2015) ............................................................................. 16 Table 2-5. HI-GAP land cover classes and area distribution in Launiupoko hydrologic unit. (Source: HI-GAP, 2005) ................................................................................................................................. 17 Table 2-6. Drought risk areas for Maui. (Source: University of Hawaii, 2003) ............................................................ 18 Table 3-1. Information of wells located in Lauiniupoko hydrologic unit (Source: State of Hawaii, Commission on Water Resource Management, 2015d). ............................................................................... 30 Table 3-2. Selected natural-flow duration discharge exceedance values from a historic (1911- 1917) gaging station (#16644000) and current (1984-2013) partial record gaging station for the Launiupoko hydrologic unit. (Source: Cheng 2014) ........................................................................... 32 Table 4-1. List of commonly mentioned native stream organisms. (Source: State of Hawaii, Division of Aquatic Resources, 1993) ............................................................................................................ 37 Table 6-2. Hawaii Stream Assessment indicators of riparian resources for Launiupoko hydrologic unit. ................................................................................................................................................................ 44 Table 6-2. Management areas located within Launiupoko hydrologic unit. (Source: State of Hawaii, Division of Forestry and Wildlife, 2008a). .......................................................................................... 45 Table 6-3. Watershed partnerships associated with the Launiupoko hydrologic unit. (Source: State of Hawaii, Division of Forestry and Wildlife, 2008b) ....................................................................................... 45 Table 6-4. Distribution of native and alien plant species for Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015f) .................................................................................................... 46 Table 6-6. Density of threatened and endangered plants for Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015i) ..................................................................................................... 46 Table 6-6. Estimated Net Present Value (NPV) for Koolau [Oahu] Forest Amenities. (Source: Kaiser, B. et al., n.d.) ..................................................................................................................................... 47 Table 12-1. Tax map key parcels with associated Land Commission Awards for the Launiupoko hydrologic unit. ............................................................................................................................................... 63 Table 12-2. Summary of water use calculated from loi and loi complexes by island, and the entire state. (Source: Gingerich et al., 2007, Table 10) .......................................................................................... 64 Table 12-3. Water-temperature statistics based on measurements collected at 15-minute intervals for loi complexes on the island of Maui. (Source: Gingerich et al., 2007, Table 7) ....................................... 64 Table 12-4. Cultural resource elements evaluated as part of the Hawaii Stream Assessment for Launiupoko Stream. ....................................................................................................................................... 66 Table 13-1. Current surface water diversions in Launiupoko Stream (Source: State of Hawaii, Commission on Water Resource Management, 2015) .................................................................................. 71 Table 13-2. Registered diversions in the Launiupko hydrologic unit. .......................................................................... 72 Table 13-3. Agricultural Lands of Importance to the State of Hawaii and area distributions in the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015g) ....................................... 76 Table 13-4. Agricultural land uses and area distributions in the Launiupoko hydrologic unit. (Source: State of Hawaii, Office of Planning, 2015h) ..................................................................................... 76 v Table 13-5. Agricultural operation, primary crop and acerage, secondary crop and acerage, and landscaping acerage by TMK in the Launiupoko Water Company service area. ........................................... 81 vi Acronyms and Abbreviations AG agricultural ALISH Agricultural Lands of Importance to the State of Hawaii ALUM agricultural land use maps [prepared by HDOA] BFQ base flow statistics BLNR Board of Land and Natural Resources (State of Hawaii) C-CAP Coastal Change Analysis Program cfs cubic feet per second Code State Water Code (State of Hawaii) COM commercial Commission Commission on Water Resource Management (DLNR) CPRC Compilation of Public Review Comments (PR-2008-07, CWRM CWA Clean Water Act (EPA) CWRM Commission on Water Resource Management (State of Hawaii) DAR Division of Aquatic Resources (State of Hawaii) DHHL Department of Hawaiian Home Lands (State of Hawaii) DLNR Department of Land and Natural Resources (State of Hawaii) DOH Department of Health (State of Hawaii) DWS Department of Water Supply (County of Maui) EA Environmental Assessment EIS Environmental Impact Statement EPA United States Environmental Protection Agency FEMA Federal Emergency Management Agency (Department of Homeland Security) FILEREF File Reference [in the Commission’s records of registered diversions] ft feet gad gallons per acre per day GIS Geographic Information Systems G.L. Government Lease GOV government gpm gallons per minute Gr. Grant HAR Hawaii Administrative Rules HC&S Hawaiian Commercial and Sugar Company HDOA State Department of Agriculture (State of Hawaii) HI-GAP Hawaii Gap Analysis Program HOT hotel HSA Hawaii Stream Assessment IFS instream flow standard IFSAR Instream Flow Standard Assessment Report IND industry IRR irrigation requirements IWREDSS Irrigation Water Requirement Estimation Decision Support System KAA Kekaha Agriculture Association KIUC Kauai Island Utility Cooperative LCA Land Commission Award LUC Land Use Commission (State of Hawaii) MECO Maui Electric Company MF multi-family residential mgd million gallons per day Mgal/d million gallons per day mi mile MOU Memorandum of Understanding na not available vii NAWQA National Water Quality Assessment (USGS) NHLC Native Hawaiian Legal Corporation NIR net irrigation requirements NPDES National Pollutant Discharge Elimination System NPV Net Present Value NRCS Natural Resource Conservation Service (USDA) NVCS National Vegetation Classification System por. Portion REL religious RMT R.M. Towill Corporation SCS Soil Conservation Service (United States Department of Agriculture) Note: The SCS is now called the Natural Resources Conservation Service (NRCS) SF single family residential SPI Standardized Precipitation Index sq mi square miles TFQ total flow statistics TFQ50 50 percent exceedence probability TFQ90 90 percent exceedence probability TMDL Total Maximum Daily Load TMK Tax Map Key UHERO University of Hawaii’s Economic Research Organization USDA United States Department of Agriculture USFWS United States Fish and Wildlife Service (Department of the Interior) USGS United States Geological Survey (Department of the Interior) WMI West Maui Investments, LLC WML West Maui Land Company WQS Water Quality Standards WRPP Water Resource Protection Plan (Commission on Water Resource Management) WTF water treatment facility viii