Hydrogeology and Water Resources of the Hopi Reservation, Arizona Hopi Water Resources Program Lionel Puhuyesva – Director James A. Duffield R.G. - Hydrogeologist The Hopi Reservation Where the Hopi have resided for over 1,500 years. A land of high desert. Marc Reisner in Cadillac Desert “A semidesert with a desert heart” Water in the High Desert Where residents depend on groundwater. A land of violent summer thunderstorms Current Reservation Boundaries The Hopi Reservation is located entirely in the State of Arizona. District Six, reserved exclusively for Hopi use, consists of 2,500 square miles. Other holdings include the joint use area with the surrounding Navajo Reservation and new land ranches near Flagstaff. Hopi District Six, the Hopi Mesas The broad plateau of Black Mesa is dissected by several northeast oriented canyons that divide the plateau into fingers or mesas. The Hopi Villages are located on these southwest oriented fingers on First, Second, and Third Mesa. The Villages of Upper and Lower Moenkopi are located to the west of the main portion of the Reservation near Tuba City. The Reservation is Located in the Colorado Plateau Physiographic Region A region of relatively un-deformed rocks defined by the Grand Canyon geology. It is formed by a thick crustal block that has been resistant to deformation. This has retained the original horizontal layering of the rock. Layers of Gently Folded Sedimentary Rocks are Stacked Atop Each Other. On the Hopi Reservation Wide Mesas Are Interspersed with Broad Valleys The southern part of the Reservation is lower and semi-arid. The northern portion of the reservation includes the higher reaches of Black Mesa where the elevation approaches 7,000 feet and much of the winter precipiation falls as snow. Surface Water of the Hopi, the Little Colorado River Watershed The main reservation and the ranch lands south of I-40 are all within the watershed of the Little Colorado River. The water dis- charges to the Colorado River mainstem in the eastern Grand Canyon. Surface Water is Rare, With Streamflow Dominated by Precipitation Events Short stretches of perennial flow are fed by groundwater discharge. Here a section of Polacca Wash on the Hopi Reservation displays year around flow fed by groundwater discharge. District Six Contains Five Major Surface Water Drainages. From west to east they are: Moenkopi Wash Dinnebito Wash Oraibi Wash Polacca Wash Jeddito Wash They are characterized by intermittent flow, with short perennial reaches fed by groundwater. Though the surface water reaches and springs are of limited areal extent they are very significant to the environment and biodiversity . Groundwater of the Hopi Reservation. The hydrogeology of the Hopi Reservation is complicated, with seven different aquifers present. Unlike aquifers in the Basin and Range region where flow is between grains, the aquifers of the Hopi are characterized by secondary porosity. Primary Porosity Secondary Porosity Basin and Range Aquifer Flow is between grains in the alluvial basins of southern Arizona, fractures dominate on the Colorado Plateau. Colorado Plateau Type Aquifer Groundwater flow is predominantly through faults and fractures. Intervening fine grained layers of silt and clay don’t fracture and they form impermeable layers. The fractures in the sandstone and limestone control the presence of groundwater and the direction of flow. Aquifers of the Hopi Reservation We deal with seven aquifers on Hopi. From the highest to lowest they are: Alluvial: Along streambeds Volcanic: Hopi Buttes area “T” Aquifer: Toreva Formation “D” Aquifer: Dakota Formation “N” Aquifer: Navajo Formation “C” Aquifer: Coconino Formation “R” Aquifer: Redwall Formation T, D, N, and C are most important to tribal interests. Alluvial and Volcanic Aquifers Are of Limited Extent and Usage But they provide water for range and wildlife in remote areas. The “T” Aquifer Supplies Water to The Village Springs. The “T” Aquifer springs support They issue from the Toreva Formation. It is agriculture and cultural activities. shallow and easily impacted by nutrients, e-coli, and other human or animal activities. The “D” Aquifer or Dakota Formation The “D” is extensive across the northern portion of the reservation. However, high TDS makes it marginal for human consumption but suitable for range water use. The “N” Aquifer is the Most Important on the Hopi Reservation The Sole Source drinking water aquifer for the Hopi, it is good quality but it may exceed the arsenic mcl in places. Withdrawal impacts from mining are now being replaced by municipal uses by Navajo and Hopi. It thins to the southwest creating water supply issues in the Moenkopi / Tuba City area. The “C” Aquifer is Important for the Hopi Ranches South of I-40 The I- 40 corridor is experiencing growth and increased water usage with Twin Arrows Casino and the Red Gap Ranch water project for the City of Flagstaff. The water quality is good but degrades to the north from contact with evaporite deposits. Chevelon Creek Clear Creek The “R” Aquifer is the Deepest and Discharges at Blue Springs in the Grand Canyon Too deep to access on the Hopi Reservation the “R” Aquifer provides a drain for “C” Aquifer water recharged south and east of the main reservation. Faulting and Folding Affect Groundwater Flow on the Colorado Plateau Faulting may control flow patterns and folding can expose the water table. As the Rock Type Varies Vertically it Also Varies Laterally: Facies Changes The Navajo Sandstone, deposited 200 mya during the Jurassic Period, interfingers with the Kayenta Formation and pinches out south of Tuba City. Threats to Hopi Aquifers Alluvial/Volcanic: Grazing – overuse & E.coli. Toreva: Contamination from human activities near villages. Dakota: Minor, has naturally high TDS. Navajo: Depletion from mining and municipal uses. Cross contamination from the “D” aquifer as potentiometric head is decreased. Coconino: Increase water development and usage along the I-40 corridor. Redwall: Minor, too deep to develop. The “T”, “N”, and “C” Aquifers are the most threatened. Hopi Water Resources Program “The Hopi Tribe is a union of self-governing villages sharing common interests and working for the common welfare of all…” First Mesa ó Walpi ó Sichomovi ó Hano (Tewa) ó Polacca ó Keams Canyon Second Mesa ó Shungopavi ó Sipaulovi ó Mishongnovi Third Mesa ó Oraibi ó Hotevilla ó Bacavi ó Kykotsmovi ó Upper Moenkopi ó Lower Moencopi The mission of the Water Resources Program (WRP) is to ensure that a safe, dependable, long-term water supply is available for the Hopi people. The Water Resources Program functions as a regulatory program as well as a policy and technical support recommending body that can be utilized both by the Hopi Tribe and Villages. WRP seeks to ensure that a safe and adequate supply of clean water is available for domestic use, ceremonial use, ranching, agriculture, and wildlife. Program Background ó The WRP started its Treatment in the Same Manner as a State (TAS) process in June of 2000 ó On April 23, 2008: Region 9 announced the approval of Program Authorization (TAS) Application at April, 2008 RTOC ó On July 8, 2008 Hopi Water Quality Standards were formally approved by EPA. ó Groundwater Enforcement Ordinance #57 H-032-11 March 1, 2011 ó Wellhead and Source Water Protection Ordinance #58 H-033-11 March 1, 2011 ó Revised Hopi Water Quality Standards approved by EPA on August 24, 2011 Currently WRP receives funding from the following sources Hopi General Funds(H-13) CWA 106 CWA 319 CWA 104(b)(3) US EPA Tribal Drinking Water Set Aside -HAMP -Shungopavi Water System Improvements BOR Native American Technical Assistance Grant BIA-Tuba City Open Dump Hopi General Fund (H-13) Lionel Puhuyesva, Director Ruby Quotshinma, Secretary Avery Pavinyama, Water Tech II Max Taylor, Water Tech II Albert Silas III, Water Tech I CWA 106-Pollution Control James Duffield -Hydrogeologist Uberta Mowa-Grants Administrator CWA 319- Nonpoint Source ó Shirley Piqosa-Nonpoint Source Coordinator • Lance Talaswaima, WRP Intern Toreva Spring Hotevilla Spring CWA 104(b)(3) Wetlands Program Development ó Max Taylor-Water Tech II ó Albert Silas III- Water Tech I Infrastructure Projects ó Completion of Water Transmission Main and Reverse Osmosis Plant Upper Village of Moenkopi utilizing US EPA Tribal Drinking Water Set Aside and US Housing and Urban Development Funding Infrastructure Projects Completion of Elevated Water Storage Tank and Transmission Line Village of Shungopavi utilizing US EPA Tribal Drinking Water Set Aside and US Housing and Urban Development Funding Infrastructure Projects ó Currently the WRP is working on the Hopi Arsenic Mitigation Project (HAMP) ó 5 Public Water Systems out of Compliance with Arsenic MCL (First and Second Mesa Region) which represents 8 out of the 12 villages on Hopi ó Project upon completion will cost approximately 21 million at total build-out In An Area of Little Rainfall and Complex Geology Hopi WRP Seeks to Provide Safe Sources of Water HAMP Well Meeting with EPA Sampling “N” Well “C” Aquifer well near Moenkopi While Protecting the Environment Uberta Mowa Wendell Smith reviewing grants. Inspecting potential 319h project sites. Albert Silas sampling springs. Sampling truck So the Resources Known to Previous Generations Can Be Enjoyed By Future Generations Thank You From the Hopi Tribe Water Resources Program .