During rainy seasons, the Flood Control District redirects large amounts of stormwater into dams, channels and basins to limit flooding risk. Most if not all of rain that falls in Maricopa County comes in contact with a District facility. This provides many opportunities for water conservation.
However, given the scarcity of water as a resource, the District is researching innovative ways to conserve water and demonstrate alternative stormwater management techniques.
The District moved to its current location at the Durango Campus when the Administration Building was completed in 1991. Over the last 30 years, landscape improvements and irrigation modifications were minimal and centered primarily on maintenance needs. This left dated landscaping and an aging irrigation system.
With a framework set by the Durango Campus Master Plan from 2017, the District advanced the effort by creating the Durango Campus Landscape and Water Conservation Retrofit Feasibility and Costing Assessment – completed in October 2019. During early stages of the study and concept creation, it was decided that GI/LID features could be located to create a site-wide stormwater management system. In order to achieve the three main goals, the design would need to utilize virtually every drop of water that falls on the District’s property more intentionally. This equates to the design of many, smaller GI/LID features throughout the site.
Landscape Architecture for us is a design practice that promotes finding the connections between ideas of water conservation and the flood control solutions we are looking for. We want to “co-locate” benefits and provide people and the environment with multiple benefits on one site.
Regional Flood Control Projects
Rather than scraping the site clean to construct a project and leave it behind, we study a project site closely to identify areas that we can leave undisturbed. We also take note of the existing vegetation so we can mimic that with our planting.
Neighborhood Flood Control Projects
Rather than simply constructing a basin and putting a fence around it, there are opportunities to make that land useful for more than just flood control such as building a public space like a park.
The tall-pot nursery at the Flood Control District was established in 2002. After seeing the success of using tall-pot grown trees at Arizona Game and Fish and Scottsdale Community College projects, Project Manager Theresa Pinto started the District’s Tall Pot Nursery. 1000 trees were produced in the first year despite the shoestring budget. Currently, the nursery has the capacity for 8500 trees with 4000 growing this season.
Most desert species have long tap roots that reach to find moisture. The length of these roots are several times the height of the above ground stems. Tall-pots mimic growth characteristic of native desert trees. In a traditional container, tap roots grow around and around in the bottom causing the need to spread the root by hand when planting. The tap root then has to reorient and grow towards moisture. The root will spread but shallow. If not irrigated, the tree can become stressed or die before reaching soil moisture. Conversely, the long tube of a tall-pot allows the tap root to follow their natural tendency to reach for soil moisture. Even without supplemental irrigation, this slight head start is often the difference between tree survival and mortality.
Stormwater runoff can be a leading cause of pollution in the dry washes, District structures and rivers in Maricopa County. Trash, such as plastics, cigarette butts and other non-biodegradable products, gets swept into the drainage system with stormwater runoff. Chemical and bacterial contaminants such as fertilizer, pesticides and animal waste are also spread through, and pollute, this untreated runoff. The District provides services and a robust operation and maintenance department to minimize the amount of trash and pollutants flowing through our storm drainage system, thereby enhancing the cleanliness of the water to our local waterways. In addition, most new developments are required to retain the first half inch of runoff to further reduce pollutants through District Right of Way.