Changes

Visual Inspection (Level 1)

Visual Inspection (Level 1)<br>

This qualitative method is low cost and requires minimal effort to conduct. Visual inspection should be used as an initial step to determine if the LID practice is operating properly. Visual inspections can be performed during dry weather and wet weather to identify situations where water is ponding for longer than intended (24 hours).

This qualitative method is low cost and requires minimal effort to conduct. Visual inspection should be used as an initial step to determine if the LID practice is operating properly. Visual inspections can be performed during dry weather and wet weather to identify situations where water is ponding for longer than intended (24 hours).

Surface Infiltration Capacity Testing (Level 2)

Surface Infiltration Capacity Testing (Level 2)<br>

Using infiltrometers or permeameters to measure the hydraulic conductivity at several locations in the LID feature at various times of year can quantitatively verify that the practice is capable of performing as intended.

Using infiltrometers or permeameters to measure the hydraulic conductivity at several locations in the LID feature at various times of year can quantitatively verify that the practice is capable of performing as intended.

Synthetic Runoff Testing (Level 3)

Synthetic Runoff Testing (Level 3)<br>

Using clean water from a fire hydrant or water truck, synthetic runoff testing can measure the performance of an LID feature in a controlled environment. In order for synthetic runoff testing to be feasible, a series of conditions must be met:

Using clean water from a fire hydrant or water truck, synthetic runoff testing can measure the performance of an LID feature in a controlled environment. In order for synthetic runoff testing to be feasible, a series of conditions must be met:

*A water supply that can deliver the required discharge and volume requirements must be available

*A water supply that can deliver the required discharge and volume requirements must be available

Long-term Monitoring (Level 4)

Long-term Monitoring (Level 4)<br>

Monitoring offers a comprehensive approach to assessing peak flow reduction and water volume reduction. These reductions can be quantified by completing a water budget during natural storm events, specifically through the measurement of inflow and outflow. Long-term monitoring is especially recommended if the LID feature that is the subject of the test is the first of its kind in its given jurisdiction, if geologic conditions pose a concern, or if the feature is being implemented to protect sensitive and significant natural features. It is important to recognize, however, that the unpredictability of natural storm events can lead to inaccuracies in data collection. Furthermore, long-term monitoring generally has the highest cost of the four levels of monitoring.

Monitoring offers a comprehensive approach to assessing peak flow reduction and water volume reduction. These reductions can be quantified by completing a water budget during natural storm events, specifically through the measurement of inflow and outflow. Long-term monitoring is especially recommended if the LID feature that is the subject of the test is the first of its kind in its given jurisdiction, if geologic conditions pose a concern, or if the feature is being implemented to protect sensitive and significant natural features. It is important to recognize, however, that the unpredictability of natural storm events can lead to inaccuracies in data collection. Furthermore, long-term monitoring generally has the highest cost of the four levels of monitoring.