The Riparian Preserve At Water Ranch

By Carol Shuler & Joe Donaldson

Lighting is limited to the concrete paths surrounding the urban fishing lake. A series of sturdy signs provide rich, educational tools for students of all ages. Interpretive signage describes the mechanics of the wetland project. The signs illustrate to visitors how the water is reclaimed, how it will be used during its peak season, ethnobotanical plan uses and the association between habitat and wildlife.
Photo by Carollo Engineers

From mundane cornfield to birding hotspot, the Riparian Preserve at Water Ranch was the vision of Lonnie Frost, former Public Works Director at the Town of Gilbert, Arizona. Desiring to maximize the use of tax dollars, Frost believed multiple uses could be compatible on the site and provide a unique recreation and educational opportunity in the region.

The highly creative team comprised of Jones & Stokes Associates, C.F. Shuler, Inc. and Carollo Engineers was selected to meet the challenge. In this desert state with highly regulated water use, even treated waste water is highly regarded. It is used to irrigate parks and golf courses, fill artificial lakes, and banked in underground aquifers for future use. One method of infiltration is through percolation in large shallow basins with wet/dry sequences.

At Gilbert, Arizona’s wetland preserve, fishing is available in an urban recreational lake. The lake is filled from a shallow aquifer well and stocked by Arizona Game & Fish Dept. An accessible path and trail system crosses between and around the various ponds.
Photo by Carol Shuler

At this site, 70 acres of ponds can accommodate up to 4 million gallons per day of tertiary treated effluent. Recharge of reclaimed water has helped improve water quality in the aquifer by diluting concentrations of dissolved solids and nitrates from agricultural operations. Water pumped from the shallow aquifer meets all drinking water standards and is suitable for full body contact. Since Gilbert began groundwater recharge activities in 1989, the groundwater level has risen from 160 feet to 120 feet below the surface.

Riparian and wetland ecosystems contain some of the scarcest and most valuable habitats in the Sonoran Desert. These once extensive habitats are now found only in isolated locations. Diverse species depend on these rare habitats for survival, and large concentrations of endangered species are found in or near the state’s riparian areas. Activities such as groundwater pumping, stream impoundment and diversion, and channelization have contributed substantially to the near extinction of these valuable ecosystems in the desert southwest.

A play area attracts visitors near the main entry. Following citizen desires, no manufactured play equipment is at the park. Undulating grassy knolls entice children to enjoy the outdoors by rolling down hills. A curvilinear wall rising out of the ground invites children to walk on it and climb over, under or through. Detail of ants are etched on top of the custom playwall. Life size silhouettes of birds allow children to compare their own height to that of the birds.
Photo by Photo by David Caywood

The Riparian Preserve helps restore some of the region’s riparian and wetland resources. The facility provides important habitat for a variety of wildlife, especially birds. The Preserve contains fourteen distinct habitat zones, including eight riparian habitat types found in the region.

Signage identifies each habitat and provides pertinent information and lists at least one Arizona location. Over 100 plant species totaling more than 25,000 plants vegetate this former cornfield.

Children can work an old-fashioned hand pump making water stream downhill past sand-filled basins into which water may be diverted. Atop a berm bordering the play area, an undulating, seat-height serpent with colorful graphic patterns draws attention to itself as a respite from walking or playing. Designs on cubes stimulate discussions on nature. The solar system cube to the left sports a sun dial.
Photos by Photo by David Caywood

Features of the habitat design and management for the Preserve that contribute to its diversity and richness include:

• Large basins that allow birds to maintain comfortable distances from people;Meandering edges and varied side slopes of the basins;Selection and placement of vegetation to provide structural diversity;Islands for roosting, resting and nesting;Opening in basin edge vegetation to create flyways that attract larger birds;Controlled after-hours access so birds can rest and feed undisturbed;Gates on some trails to control access to sensitive areas during breeding season;An absence of lighting in primary habitat areas;Landforms, structures, and vegetation placed as screening to reduce public disturbance of wildlife;Leash laws, restrictions on bicycles and prohibition of equestrian use of trails within the Preserve; and
• Informational signs explaining rules and reasons for restrictions.

At this site, 70 acres of ponds can accommodate up to 4 million gallons per day of tertiary treated effluent. Recharge of reclaimed water has helped improve water quality in the aquifer by diluting concentrations of dissolved solids and nitrates from agricultural operations. Water pumped from the shallow aquifer meets all drinking water standards and is suitable for full body contact. Since Gilbert began groundwater recharge activities in 1989, the groundwater level has risen from 160 feet to 120 feet below the surface.

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The recreational elements of the Preserve compliment its habitat areas. The forms, images, textures and colors used are based on themes of wildlife, water and desert ecosystems.

Environmental education is also an integral element of the Preserve’s design. Twelve interpretive exhibits educate visitors about wildlife, habitats, water conservations and the local region.

An ethnobotanical interpretive garden features culturally important plants of the Sonoran Desert. Controlled after-hours access makes it possible for birds to rest and feed undisturbed while gates on some trails control access to sensitive areas during breeding season. In addition, there is an absence of lighting in primary habitat areas.
Photo by Carol Shuler

Additional recreation and environmental education components include:

• A five-acre recreational and fishing lake with a floating boardwalk;Over four miles of trails;An ethnobotanical garden showcasing traditionally important native plants;Seatwalls and gates enhanced with wildlife images;An unconventional, custom play area with wildlife-themed structures;Outdoor classroom areas;Picnic and shade structures; and
• An entry plaza with curvilinear walls and paving patterns that suggest the flow of water.

A floating boardwalk traverses the urban recreational lake facilitating views into, and walks through, the adjacent marsh. Islands in the basins provide refuge only accessible by birds. The Snowy Egret and Great Blue Heron are among the water fowl found in the secluded lagoons at the Riparian Preserve.

Given the Preserve’s urban location and primary function as a groundwater recharge facility, certain limitations and design tradeoffs related to the quality of habitat that could be created and maintained at the facility were unavoidable.

Wildlife observation areas range from blinds made of pipe rail and corrugated steel coated with artificial desert varnish, to raised overlooks or simple earthen mounds. Although the highest elevation is an overlook 15 feet above natural grade, the path system is entirely accessible. Once on this lookout, visitors have views to the distant mountain ranges and into a marsh below.

Over 250 species of birds have been identified at the Preserve. Birder’s Word magazine highlights the site as a US birding hotspot and the National Audubon Society identifies it as an Important Bird Area (IBA). The Riparian Institute provides 16 youth and scout programs, a volunteer program, research opportunities and maintenance. Go to www.riparianinstitute.org for further details.
Photos by Carol Shuler

Factors contributing to these limitations include:

• Public use and associated noise and activities;Access by domestic animals;Restrictions on the number of wildlife sanctuary areas;Maintenance of vegetation for safety and aesthetics, limiting cover for wildlife;Control of insects for safety and comfort, limiting foraging opportunities;Restrictions on vegetation that provide good habitat but may appear “messy” (e.g., female cottonwoods and native palms).Periodic vegetation removal from the basins to maintain percolation rates; and
• Temporary disturbance of wildlife during periodic maintenance operations.

Gates allow seasonal blockage of certain trails to encourage nesting. Each gateway features the silhouette of a different bird species. The great blue heron gate is constructed of pipe rail, welded wire fabric and rebar.
Photo by Joe Donaldson

The town also has a monitoring program using trained volunteers to assess bird use at the Preserve. The town and local school districts have developed materials and programs as part of the district’s science curriculum. Community volunteers have assisted with planting and maintenance activities. Other communities in the region are beginning to plan similar types of facilities. Due to the success of the Preserve, Gilbert plans development of similar projects in the future.

Burrowing owls disturbed by development have been relocated to the Preserve.
Photo by Joe Donaldson

Perhaps the best testament to the success of the town’s two multi-purpose recharge facilities is that they are working as intended, recharging the groundwater, contributing to water reuse, attracting diverse wildlife, providing educational and recreational opportunities, and providing aesthetic and functional open space for the community.

From dawn to disk the trails are used by walkers, joggers and birders. Over four miles of trails serpentine through the preserve.
Photo by Carol Shuler

PROJECT:

• Riparian Preserve at Water Ranch
• Town of Gilbert, Arizona

CLIENT:

• Town of Gilbert, Arizona
• Guy Carpenter, Water Resources Manager

DESIGNERS:

• Jones & Stokes Associates, Inc. (Environmental Planners)Joe Donaldson – Design Project ManagerCarollo Engineers (Civil Engineers)C.F. Shuler, Inc. (Landscape Architect)Carol Shuler – Lead Landscape ArchitectWild Seed (Habitat Consultant)
• Blue Mesa Studio (Aquatic Consultant)

CONTRACTORS:

• Hunter Contracting, General
• Valley Crest, Landscape

SITE AMENITIES: