HOW TO OPTIMIZE YOUR GREEN INFRASTRUCTURE INVESTMENT WITH TESTING - - PowerPoint PPT Presentation

HOW TO OPTIMIZE YOUR GREEN INFRASTRUCTURE INVESTMENT WITH TESTING AND MONITORING

Do you know how your green infrastructure is performing? Andy Sauer, PE, ENV SP, Project Manager

GREEN INFRASTRUCTURE

Sometimes referred to as stormwater best management practices (BMP), green infrastructure are dynamic systems that use natural features like soils and vegetation to manage stormwater and are

• ften used for:
• Water quality regulatory compliance
• Enhancing open spaces
• Creating more resilient urban development

To avoid costly maintenance, invasive weeds and poor performance — begin optimizing green infrastructure by knowing:

• What distinguishes good from bad design
• What vegetative bioretention cells are and how they work
• Testing and monitoring techniques
• Benefjts of adaptive design

GREEN INFRASTRUCTURE DESIGN DONE RIGHT

Good design

• Optimizes soil infjltration rates and plant performance
• Enables adaptations after construction to meet actual conditions
• Reduces maintenance costs over time
• Improves performance over time
• Allows monitoring and testing throughout the life of the design

Poor design

• Doesn’t retain enough water for plant life
• Requires multiple replantings
• More expensive over time
• Reduces performance over time

VEGETATIVE BIORETENTION CELLS

To best incorporate green infrastructure, vegetative bioretention cells are an efgective design technique:

• Bioretention cells allow for largest stormwater capture in a

small footprint

• Engineered soils within bioretention cells allow for enhanced

design control more than natural systems, such as rain gardens

BIORETENTION CELL MONITORING

Soil profile analysis indicates moisture levels in root zones as vegetation becomes established. Flow monitoring and precipitation gauges indicate stormwater runofg volume and infmow/outfmow rates. Infiltration monitoring using the ponding method indicates infjltration rates and water-holding times.

WHAT’S IN A SOIL PROFILE?

• Soil moisture
• Soil temperature
• Infjltration rates

WHAT’S INVOLVED WITH FLOW MONITORING AND PRECIPITATION GAUGES?

Flow in and out

• Confjrm design fmow rates
• Calculate volume of water retained

On-site precipitation monitoring

• Monitor site-specifjc rain events
• Calculate runofg volume captured by bioretention cell

Ponding (water level) monitoring

• Understand real rainfall event ponding depth with time
• Calculate infjltration rates
• Understand holding times for specifjc events
• Utilize to adjust outfmow for optimal retention and plant performance

Traditional method — Infiltrometer

• Infjltration rate

WHAT’S INVOLVED WITH INFILTRATION MONITORING?

BIORETENTION TESTING

Soil moisture

• Understand moisture levels at difgerent soil depths
• Used over time as soil moisture profjles change
• Regulate stormwater discharge to maximize plant performance

Methods:

• Soil moisture sensors
• Neutron probe
• Tensiometers

APPLYING ADAPTIVE DESIGN

Optimize green infrastructure performance

• Improved plant performance
• Match water retention times to maximize soil moisture storage
• Maximize soil infjltration and plant evapotranspiration

Improve future green infrastructure design

• Inform owner of the right soil mix for location
• Update design standards to include better soil specifjcation

Andy Sauer, PE, ENV SP Project Manager 816-448-7578 linkedin.com/in/andysauer

Andy Sauer is a project manager/green infrastructure and stormwater leader with Burns & McDonnell. As a senior water resources engineer, Andy has more than 10 years of experience in urban wet weather issues. Andy currently serves on the national Water Environmental Federation (WEF) Community

• f Practice on Sustainability. He earned a bachelor’s degree in

agricultural engineering and a master’s degree in agricultural and biological systems engineering from the University of Nebraska-Lincoln.