Forest Uplands contribute less than 10% of the FSP loading, but more than a quarter of the total phosphorous loading to Lake Tahoe. Select Performance Measures (PMs) are tracked and reported based on the finding that the vast majority of the pollutant loading from undeveloped lands originates from paved and unpaved roads, disturbed areas and public facilities. As precipitation falling on these surfaces runs off, it picks up particles and nutrients. Unmitigated, these pollutants are deposited into nearby surface waters that drain to Lake Tahoe.
The Miles of Roads Inspected and Maintained TMDL PM tracks the miles of permanent paved and unpaved forest roads that are inspected and/or maintained to reduce stormwater pollution from the Forested Uplands each year. Road inspections must be done in person to check for repair or improvement needs on existing stormwater retrofits. Road maintenance includes the implementation of repairs and improvements to existing stormwater retrofits as needed. This TMDL PM only measures permanent roads that are part of a landowners road network, and does not track roads that are built and removed for specific projects such as vegetation management activities.
The Miles of Roads Created TMDL PM tracks the miles of permanent paved and unpaved roads, that are created in the Forested Uplands each year. Roads are considered created when they are added to the permanent road network of the road owner, whether for storage or for regular use. The Miles of Roads Created TMDL PM complements the Miles of Roads Treated TMDL PM by providing a full picture of the change in the total miles of forest roads in the Tahoe Basin on an annual basis.
The Disturbed Area Restored, Enhanced or Created PM tracks the total acres of land in the Forested Uplands with compacted soil, disturbed vegetation and/or impacted hydrology that is restored, enhanced or created each year. Disturbed areas include areas tracked as soft coverage by the EIP PM Impervious Coverage Retired. This PM does not track actions to reduce stormwater runoff on forest roads. Forest roads are tracked using the Miles of Roads Treated, Miles of Roads Inspected and Maintained and Miles of Roads Created TMDL PMs.
Data displayed currently includes improvements accomplished by TMDL Urban Implementing Partners. TMDL Management Agencies are working on update to display only accomplishments completed on non-urban roads.
The amount of forestland roads that are retrofitted or obliterated to reduce stormwater pollution through capital improvements. This PM is reported in three categories of treatment priority based on water quality risk. Treating high-priority roads reduces stormwater pollution and cost-effectively improves the clarity of Lake Tahoe.