Overview​

Since 2011 WEEL has been studying the Tres Rios Constructed Wastewater Treatment Wetlands, which are owned operated by the City of Phoenix Water Services Department. While constructed treatment wetlands (CTW's) are well established as an effective and sustainable solution to the issues associated with urban water treatment and reclamation, how these systems operate in aridland environments compared to their more traditional mesic and temperate settings is not well understood. As such, we seek to better understand the ecosystem-scale dynamics of this urban oasis. Located just south of S 91st Ave and W Broadway Road in metropolitan Phoenix, Tres Rios is an accessible and enriching field laboratory for educational research experiences.

Methods and Approaches

We use a variety of different approaches and methods to understand the ecosystem dynamics of the Tres Rios Wetlands. Our methods include:
  1. Above- and below-ground primary productivity (pictured right)
  2. Above- and below-ground plant tissue nutrient analysis
  3. Transect-specific and whole-system water quality
  4. Direct transpiration measurements
  5. Soil biogeochemistry
  6. Aquatic net primary productivity

For more detailed information on some of these methods, please see our current Tres Rios publications listed below.

Key Findings

  1. Plant community diversity appeared to improve the system's ability to remove and retain nitrogen.
  2. High atmospheric water losses due to evaporation and transpiration, while originally thought to potentially negatively affect system performance, appear to be enhancing treatment opportunities via a plant-mediated flow-path we are calling a "biological tide."
  3. This "biological tide" phenomenon may actually make aridland treatment wetlands as if not more effective in delivering the ecosystem services (nitrogen removal) expected of them than their more mesic counterparts.

Related Products

Bois, P, DL Childers, T Corlouer, J Laurent, A Massicot, CA Sanchez, and A Wanko. 2017. Confirming a plant-mediated “Biological Tide” in an aridland constructed treatment wetland. Ecosphere 8(3): e01756. 10.1002/ecs2. 1756

NA Weller, DL Childers, L Turnbull, RF Upham. 2016. Aridland constructed treatment wetlands I: Macrophyte productivity, community composition and nitrogen uptake. Ecological Engineering 97:649–657. doi.org/10.1016/j.ecoleng.2015.05.044
​
CA Sanchez, DL Childers, L Turnbull, RF Upham, and NA Weller. 2016 . Aridland constructed treatment wetlands II: Plant mediation of surface hydrology enhances nitrogen removal. Ecological Engineering 97:658–665 doi.org/10.1016/j.ecoleng.2016.01.002