Pima County Regional Flood Control District Monthly Brown Bag
Speaker: Ricardo Aguirre, Holistic Engineering and Land Management, Inc.
Date: Wednesday, September 13, 2017
Time: 12:00 – 1:00 PM
Location: 9th Floor Public Works Building, 201 N. Stone, Tucson AZ, 85701
Flooding, soil erosion, and dust storms are all symptoms of degraded land known as desertification, which results in an ecological system that is out of balance, where both the water cycle and the nutrient cycle are no longer effective. To mitigate these symptoms, engineers will use technology, such as machinery to build channels, pipes, and storage basins. Technology also comes in the form of chemicals, such as liquid fertilizers, soil stabilizers, or various types of soil amendments used in industrial agricultural practices. These “improvements” are symptomatic relief, “Band-Aid” strategies that continue to adversely impact the environment while also imposing long-term costs due to maintenance.
Holistic Management endeavors to attack the root cause of the problem by restoring soil organic matter, which is the fundamental property of soil that determines its water holding capacity. On average, for every one percent of soil organic matter, approximately 60,000 gallons of water per acre can be retained. Most rangelands worldwide have been degraded so badly that the soil organic matter is less than two percent. In many places like the arid Southwest, soil organic matter has reached zero percent, resulting in totally bare soil, no water-holding capacity, and conditions leading to soil crusting, soil loss, and lethal dust storms. Embarking on an effort to restore soil organic matter would have significant beneficial impacts to the environment. More specifically it would reduce flooding, eliminate soil erosion, improve stormwater quality, and help prevent dust storms. By improving the water holding capacity of the land, Holistic Management could also benefit agricultural programs. The result would be a multitude of benefits that work in tandem.
This talk will compare centralized versus decentralized stormwater management and discuss historic land conditions, the brittleness scale, the effective water cycle, ways livestock can be used rehabilitate degraded land, and a new approach to site design.