Santa Cruz AMA Virtual Tour Santa Cruz AMA Virtual Tour September 2000

Santa Cruz AMA Virtual Tour In …the Code created the Tucson AMA But after 14 years... …the Code created the Santa Cruz AMA Santa Cruz AMA Virtual Tour Introduction

Introduction

Introduction T he management goal of the Santa Cruz AMA is to maintain a safe-yield condition in the active management area and to prevent local water tables from experiencing long-term declines. §45-562(C) Nogales I-19 SR-82 PIMA COUNTY Amado SANTA CRUZ COUNTY Tubac Rio Rico

Santa Cruz AMA Virtual Tour Land Ownership Introduction Coronado National Forest Coronado Nat’l Forest Coronado Nat’l Forest Land Ownership State Land State Land State Land State Park SCAMA covers 716 square miles

Santa Cruz AMA Virtual Tour Introduction 37,000 people Nogales, Rio Rico, Tubac and Amado Population concentrated in Nogales and along the Santa Cruz River Large fluctuations in temporary residents Nogales Tubac PIMA COUNTY Rio Rico SANTA CRUZ COUNTY Amado Demographics

Santa Cruz AMA Virtual Tour United States Mexico ‘Ambos Nogales’ Binational Issues Introduction Nogales, AZ population approximately 23,000 Nogales, Mexico population approximately 300,000 Binational watershed Well fields in Arizona downstream from well fields in Sonora Impact in AZ from water policies in Mexico Mexico’s right to return effluent flows Impact of additional development in Mexico

Santa Cruz AMA Virtual Tour 18-20" 16-18" 14-16" 20-22" 18-20" 28-30" 20-22" 20-22" 24-26" 24-26" 20-22" 26-28" 20-22" Physical Setting Climate Mean annual precipitation

Santa Cruz AMA Virtual Tour Physical Setting Surface Water Santa Cruz River Sopori Wash Sonoita Creek Nogales Wash Josephine Canyon

Santa Cruz AMA Virtual Tour –Nogales Formation oldest & deepest layer low yield –Older Alluvium large storage low transmissivity –Younger Alluvium productive & heavily used 40 to 150 feet thick Bedrock Nogales Formation Older Alluvium Younger Alluvium Physical Setting Three layer aquifer system Hydrogeology

Santa Cruz AMA Virtual Tour Blue: exempt Red: non-exempt Wells Physical Setting ~1,300 registered wells Two-thirds of wells are exempt

Santa Cruz AMA Virtual Tour Demand 25,800 AF 10,300 AF 7,300 AF 1,500 AF 537 AF 8,600 AF All water uses

Santa Cruz AMA Virtual Tour Supply Low Range/Poor Year Estimate (10th Percentile) High Range/Good Year Estimate (90th Percentile) Total supply  39,600 Total supply  142,900

Santa Cruz AMA Virtual Tour Budget

Budget During wet years the aquifers get replenished and more water leaves the AMA The use of a long term water budget could be misleading due to limited storage capacity and fast movement of water in the younger alluvium Safe yield is assumed to be achieved in the long term In dry years the aquifers are overdrafted

Santa Cruz AMA Virtual Tour Historic Trends

Santa Cruz AMA Virtual Tour Winter mix, bermuda, & fescue Mostly used for cattle pasture 65 irrigation rights (>10 AC) 24 rights using >50% of allotment Agriculture One irrigation right accounts for 1/3 to 1/2 of total use Rio Rico irrigation acres Tubac irrigation acres Sopori irrigation acres

Santa Cruz AMA Virtual Tour Municipal Four large providers (~90% of muni. demand) 750 domestic exempt wells Ten Small providers Tubac Valley W.C. Valle Verde W.C. Rio Rico Utilities City of Nogales W.C.

Santa Cruz AMA Virtual Tour Four golf courses One regulated sand & gravel facility Industrial Rio Rico Tubac Palo Duro Kino Springs San Xavier Sand & Gravel

Santa Cruz AMA Virtual Tour Riparian ~26,000 AF of riparian evapo- transpiration Nogales International Wastewater Treatment Plant (NIWWTP) is primary source of water NIWWTP

Santa Cruz AMA Virtual Tour Projections

Issues and Challenges Conjunctive Management of Surface Water and Groundwater - Impact on surface water rights by groundwater pumping - Community desire to protect riparian habitat - Physical challenge in developing recharge facilities - Difficulty in measuring achievement of management programs Maintain the AMA goal in a highly variable system Lack of access to renewable water supplies

Santa Cruz AMA Virtual Tour Issues and Challenges Implementation of Assured Water Supply Rules Establishment of well spacing criteria Work with local water users to propose legislation to create a replenishment/water district authority Continue dialogue with local, state and federal agencies in Mexico to negotiate agreements in future effluent uses

Santa Cruz AMA Virtual Tour Increase in hydrological data collection Evaluation of natural water demands and supplies Publication of the Third Management Plan as Santa Cruz AMA Establishment of binational cooperation in hydrological data collection and exchange Support the efforts to reach a surface water claims settlement prior to adjudication Refined understanding of the hydrological conditions by the development of surface and groundwater models Funding grants to explore water augmentation opportunities AMA Accomplishments

Santa Cruz AMA Virtual Tour Santa Cruz AMA