Water Resources
The Cienega Creek watershed upstream of “Pantano Dam” covers over 450 square miles in area, which includes the Empire Mountains, portions of the Whetstone, Santa Rita and Rincon Mountains, and much of the broad valley that lies in between. 
The watershed is divided into two sub-basins: the upper basin and the lower basin. The upper basin includes all of the area south of the Narrows, where groundwater is forced to the surface by shallow bedrock. The lower basin lies to the north of the Narrows and includes all of the land within the boundaries of the Preserve. Perennial stream flow occurs along reaches north of Interstate 10 in places where bedrock comes close to the surface. Surface flow ends at the Pantano Dam, where the water is diverted into a pipe and delivered to ponds located west of the Preserve and used by the Del Lago Golf Course.
The extent and amount of perennial flow within the Preserve varies seasonally due mainly to vegetative growth and rainfall. Perennial flow generally occurs between the “Tilted Beds” area and Pantano Dam. From 1999 to 2009, perennial stream lengths in this area varied from 1.5 miles to just over 4.6 miles during the summer (June) monitoring events. Base flows are generally less than one cubic feet per second in reaches where perennial flow occurs.
Groundwater levels within the Preserve range from zero feet in perennial portions to almost 200 feet at the downstream end. Seasonal variations in water levels are typical, with most rises occurring during the summer monsoon season (August and September).
Cienega Creek flows have been decreasing since 2001, based on seasonal mapping of wetted stream lengths by Pima County Association of Governments (PAG). Groundwater and surface water in the Cienega Creek watershed and Davidson Canyon sub-watershed may be at a further threat due to increased groundwater use due to land development, surface water diversions, and decreased recharge related to climate change. Understanding the source of water supporting stream flows, the nature of surface water-groundwater interactions, and the location, seasonality, and residence time of groundwater is critical for natural resource management in the region. Since 2014, the Pima County Regional Flood Control District has contracted with researchers at the University of Arizona to do comprehensive studies of groundwater, surface water and precipitation water chemistry throughout lower Cienega Creek and Davidson Canyon watersheds. Reports and project posters are listed below:
The quality of surface water within the Preserve is consistently better than state water quality standards. Designation of the perennial portions of Cienega Creek and Davidson Canyon as “Outstanding Waters of Arizona” was based, in part, on the high quality of surface water.
Links:
Reports
Outstanding Waters
Monitoring Plans
Studies
Other Information
Vegetation
Two features of the Preserve that first stand out are (1) the great diversity of plant associations observed over a relatively small geographic area and (2) the presence of riparian vegetation. The Preserve is located within a transitional zone between the Sonoran Desert and the Chihuahuan Desert. As such, nine distinct plant associations ranging from desert grass and scrublands to subtropical riparian forests occur within its boundaries. The occurrence of perennial and intermittent stream flow has helped to establish lush riparian vegetation along Cienega Creek and some of its principal tributaries.
Approximately 75% of Arizona’s wildlife species depend on riparian areas for all or part of their life cycle. However, riparian areas currently cover less than 1% of Arizona’s total land base. Over the past 100 years, many riparian areas in Arizona have been lost or highly degraded due to overgrazing, groundwater pumping, farming, water diversion, mining and the expansion of commercial, residential and industrial land uses. As a result, Cienega Creek is one of the few remaining examples of a desert riparian community.
The trees and plants found along Cienega Creek are important to the stability of the riparian community because they slow down water velocities and protect stream banks from erosion. They also provide food, cover and breeding habitat for a variety of wildlife species.
Links:
Land Cover Map
Plant Communities
Special Status Plant Species
Vegetation Studies
Preliminary Flora of the Pantano Formation, Claystone Member Deposits
Huachuca Water Umbell Report
Revegetation Projects
Pantano Jungle Restoration
Revegetating Abandoned Farmland in the Cienega Creek Natural Preserve
Invasive Species
Buffelgrass Populations Map
Non-Native Plant Species Study
Wildlife
Habitats along Cienega Creek support over 280 native species of mammals, birds, reptiles, amphibians, fish and insects that either reside in or frequently visit the Preserve. This includes over 150 species of birds. The Preserve is especially important to neo-tropical migratory birds, which seasonally utilize the area for nesting. The presence of perennial stream flow supports native frog and fish populations that are found very infrequently in the desert environment.
High vegetation density, available cover and linear configuration make Cienega Creek and its principal tributaries excellent corridors for wildlife movement between the larger protected areas of the Coronado National Forest and Empire-Cienega National Conservation Area. Protection of these resources is important to offset the fragmentation of the landscape that is occurring through urban development (i.e., housing, roads, railroad, interstate highway) and to maintain precious links in the natural landscape.
The Cienega Creek Natural Preserve is home to several Special Status Wildlife, including some native aquatic species such as the lowland leopard frog and Gila topminnow. Many of the aquatic species have disappeared or declined in other areas due to introductions of nonnative species such as the bullfrog and green sunfish, which either directly eat or out-compete the native species. You can help protect the native frogs and other wildlife by not releasing captive animals into the Preserve or surrounding natural areas.
Links:
Wildlife Studies/Projects
2004 Avian Surveys of Cienega Creek Natural Preserve
Other Information
Species Lists
Biological & Wildlife Movement Corridors (SDCP)
Special Status Wildlife
Bird Checklist
Cultural Resources
The Cienega Creek Natural Preserve (CCNP) encompasses a traditional route of great antiquity between the Tucson Basin and the San Pedro River Valley. The year-round presence of water has drawn people to Cienega Creek from the earliest periods of human occupation in southern Arizona. Evidence of past habitation and exploitation can be seen throughout the landscape of the Preserve, which has been occupied and used by humans for more than 12,000 years, from the end of the last Ice Age to modern times.
Small, mobile groups of people first used the landscape of the CCNP from 10,000 B.C. to A.D.200, making their living hunting small and large animals and gathering plants. A major shift in occupation occurred around A.D.200, when people began living a more settled life in hamlets and small villages along rivers and streams. Populations increased as people developed agriculture and other new technologies, like pottery for storage, to support this settled way of life. This period saw the rise of the well-known Hohokam culture, who occupied southern Arizona in larger village settlements associated with waterways and arable land. Hohokam settlements were abandoned by A.D.1450, but today the question of what happened to the Hohokam remains unanswered. Some archaeologists believe drought and ecological collapse, or perhaps warfare, explain the dramatic drop in Hohokam populations.
Historic Spanish Colonial and Mexican settlement of the area occurred from A.D.1700 to 1856. Settlements sprang up across the region, sometimes starting with the establishment of Missions where populations concentrated in fortified Presidios (as at the Presidio del Tucson) to protect against raiding Apache groups. Mexican homesteaders and ranchers appreciated the rich environment of the Cienega Creek area, as did later American settlers following the Gadsen Purchase. The establishment of travel routes such as the Butterfield Stage Line, which passed through the Cienega Creek area, and the railroad, which arrived in 1880, helped to accelerate the growth of Tucson and surrounding communities. The railroad led to the establishment of rail depots and townsites in the Preserve, including the historic Pantano Townsite.
Ranching and farming along Cienega Creek became important to the economic development of the area and today many historic ranches dot the landscape. In 1912, Arizona achieved statehood, marking the Modern Period in Arizona. Ranching continues to be an important part of today’s economy.
The vast number of prehistoric and historic cultural resources found within the CCNP help to show the importance of this area to the human population and the critical importance of its preservation. Management of the Preserve is geared to protect these resources and continue building on our knowledge of the past.
Links:
Cultural Resources Overview
Cultural Resource Site Descriptions
Sonoran Desert Conservation Plan
Pima County Office of Cultural Resources and Historic Preservation
Recreation and Education
Recreation
The presence of clean running water, large shade trees, and mountain vistas make the Preserve a highly desirable place for human recreation, especially within the context of the surrounding desert environment. Public use of the Preserve is accommodated to the degree that such use will not result in the degradation of the natural, cultural and scenic resources of the site. Please review the list of permitted, restrictive and prohibited activities prior to planning a visit to the Preserve. A day use permit is required for entry into the Preserve by any individual or groups up to six people. Permits are provided by the Pima County Natural Resources, Parks and Recreation Department (PCNRPR).
Public access into the Preserve is currently limited to three sites: Colossal Cave Road, Three Bridges and Davison Canyon (see map). The only designated trail through the Preserve is the Cienega Creek Trail (see map), which is restricted to pedestrian use. The Arizona Trail runs through a portion of the Preserve from Agua Verde Creek through Davidson Canyon and can accommodate pedestrians, equestrians and mountain bicycles.
Education
The resources of the Preserve create numerous opportunities for scientific research. Scientific research that adds to the knowledge base of the Preserve is encouraged. Special use permits can be issued to individuals, groups or organizations for a specified period of time. Conditions may be attached to insure protection of the resources and allow access to information gained by the research. Prior to the commencement of any research project, a written proposal needs to be submitted for approval by PCNRPR and PCRFCD. Any resources research or scientific proposal that has the potential to impact cultural resources needs to be reviewed and approved by the Pima County Office of Cultural Resources and Historic Protection (PCOCRHP).
Special Use permits may also be granted to organizations and large groups for public education, volunteer efforts (trash cleanup, weed eradication), and trail rides. All proposals for group uses need to be submitted and approved by PCNRPR, PCRFCD and PCOCRHP.
Links:
Public Uses
Rules and Regulations
Pima County Natural Resources, Parks & Recreation
Arizona Trail
Management
When the Preserve was established in 1986, the Pima County Board of Supervisors adopted a Declaration of Restrictions, Covenants and Conditions stating that the Preserve is to be used “…for the purposes of the preservation and protection of the natural and scenic resources of the property,…for the benefit and protection of the County, its resources, residents, and visitors”. To accomplish this end, the District developed three management objects, which, in order of importance, are as follows: (1) to preserve and protect the perennial stream flow, (2) to preserve and protect the existing riparian vegetation and cultural resources, and (3) to provide opportunities for public recreation, education and other appropriate activities.
In order to ensure management practices consistent with the defined objectives, a management plan was developed to articulate polices or procedures and to identify specific actions that will be taken related to management of the various resources within the Preserve. 
Management of the Preserve is conducted jointly by the Pima County Regional Flood Control District and the Pima County Natural Resources, Parks and Recreation Department. Cooperative assistance is provided by Pima County Real Property, Pima County Office of Cultural Resources and Historic Preservation, and various land stewards and public volunteers.
Properties encompassing the Preserve are designated as mitigation lands under Pima County’s Multi-Species Conservation Plan (MSCP). The MSCP provides Pima County with protection for the incidental take (harassment, harm, pursuit, kill, etc.) of Federally listed species under the Endangered Species Act based on provisions described under the associated Habitat Conservation Plan. As such, the Preserve is managed to minimize and mitigate impacts to natural resources in order to maintain its status under the MSCP.
Links:
Documents
Management Plan (March 2022)
Management Plan (October 1994)
Pantano Jungle Restoration Final Report
Maps
Proposed Development Within the Preserve
Management Activities
Cienega Corridor Management Plan
Restoration of Cienega Creek Bottomlands
Volunteer Programs
Brochures
Bird Checklist
Links to related sites (will open in new window)
Arizona Heritage Waters
Arizona Trail
Arizona Wildlife Viewing Area
Aviatlas Birding Hotspot
Biological & Wildlife Movement Corridors (SDCP)
Cienega Creek Basin (ADWR)
Cienega Creek Projects (PAG)
Cienega Watershed Partnership
Cultural Resources (PCOCRHP)
Frog Conservation Project
Las Cienegas National Conservation Area (BLM)
Multi-Species Conservation Plan (Pima County)
Permits (PCNRPR)
Responsible OHV Use (AGFD)
Sonoran Desert Conservation Plan
Stream Flow Data @ Pantano near Vail (USGS)
Precipitation and Stream Flow Data (PCRFCD)