Total Maximum Daily Loads (TMDLs)
What are Total Maximum Daily Loads?
In simple terms, a Total Maximum Daily Load (TMDL) is a “pollutant budget” for a specific waterbody. It identifies the maximum pollutant load that a lake, river, or stream can receive while still meeting Nevada’s water quality standards. A TMDL determines a pollutant reduction target and allocates load reductions necessary to the source(s) of the pollutant.
TMDLs serve as the foundation for restoring impaired waters and ensuring they remain healthy for the long term.
Managing All Sources of Pollution
A TMDL provides a unified strategy to restore and protect water quality by dividing the "pollutant budget" into two categories:
- Wasteload Allocations (WLA): The portion of the budget assigned to point sources (i.e., permitted dischargers).
- Load Allocations (LA): The portion of the budget assigned to nonpoint sources, including natural background.
By addressing both point and nonpoint sources of pollution, a TMDL ensures that all contributing factors are considered in restoring and protecting the watershed.
Sustaining Water Quality Improvement
TMDLs are more than just a short-term fix for impaired waters; they are enduring frameworks for maintaining environmental health.
- Beyond Restoration: Even after a water body meets its quality standards, the strategies and allocations within a TMDL act as a vital safeguard against future degradation.
- Federal Policy: The United States Environmental Protection Agency does not consider achieving water quality standards as a valid reason to withdraw or revise an approved TMDL.
- Sustained Protection: Keeping TMDLs in place ensures that Nevada’s surface waters remain healthy, resilient, and protected for future generations.
For more information please see the TMDL Program Fact Sheet.
Approved TMDLs
| Waterbody | Reach Description | TMDL Parameters | Documents |
Brockliss Slough, including East and West Branches | From its divergence from the Carson River, West Fork to its confluence with the Carson River | Turbidity | |
Bryant Creek | From the Nevada-California state line to its confluence with the East Fork of the Carson River | Arsenic, Iron, Nickel, Total Suspended Solids (TSS), Turbidity | |
Carson River | From Weeks Bridge at Highway 95 to Lahontan Reservoir | Phosphorus (Total) | |
Carson River | From Genoa Lane to Cradlebaugh Bridge | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River | Cradlebaugh Bridge to Mexican Ditch Gage | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River | From Mexican Ditch Gage to New Empire | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River | From New Empire to Dayton Bridge | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River | Dayton Bridge to Weeks Bridge at Highway 95 | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River, East and West Forks and Carson River | Carson River, East Fork from Muller Lane to the West Fork, Carson River, West Fork from Muller Lane to the East Fork, and Carson River from the confluence of the East and West Forks to Genoa Lane | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River, East Fork | From Nevada-California state line to Riverview Mobile Home Park | Total Suspended Solids (TSS), Turbidity | |
Carson River, East Fork | From Riverview Mobile Home Park to Highway 88 | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River, East Fork | From Highway 88 to Muller Lane | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Carson River, West Fork | From the Nevada-California state line to Muller Lane | Phosphorus (Total), Total Suspended Solids (TSS), Turbidity | |
Dixie Creek | From its origin to its confluence with the Humboldt River, South Fork | Temperature | |
Hanks Creek | From its origin to its confluence with the Marys River | Temperature | |
Humboldt River | From Osino to Palisade | Phosphorus (Total), Total Suspended Solids (TSS) | |
Humboldt River | From Palisade to Battle Mountain | Phosphorus (Total), Total Suspended Solids (TSS) | |
Humboldt River | From Battle Mountain to Comus | Phosphorus (Total), Total Dissolved Solids, Total Suspended Solids (TSS) | |
Humboldt River | From Comus to Imlay | Phosphorus (Total), Total Dissolved Solids, Total Suspended Solids (TSS) | |
Lake Tahoe | The entire Lake (Nevada Portion only) | Clarity | |
Las Vegas Wash | Las Vegas Wash from the Historic Lateral to its confluence with Lake Mead | Ammonia (Total), Chlorophyll-a, Phosphorus (Total) | |
Mill Creek | From the West line of section 11, T. 45 N., R. 53 E., M.D.B. & M. to the Owyhee River | Cadmium, Copper, Iron, Dissolved Oxygen, pH, Phosphorus (Total), Temperature, Total Dissolved Solids, Total Suspended Solids (TSS), Turbidity | |
Owyhee River | From Wildhorse Reservoir to its confluence with Mill Creek | Iron, Phosphorus (Total), Temperature, Total Suspended Solids (TSS), Turbidity | |
Owyhee River | From its confluence with Mill Creek the border of the Duck Valley Indian Reservation | Copper, Iron, Phosphorus (Total), Temperature, Total Suspended Solids (TSS), Turbidity | |
Rio Tinto Gulch | From its origin to Mill Creek | Cadmium, Copper, Iron, Dissolved Oxygen, pH, Phosphorus (Total), Temperature, Total Dissolved Solids, Total Suspended Solids (TSS), Turbidity | |
Truckee River | From East McCarran Blvd to Lockwood | Nitrogen (Total), Phosphorus (Total), Total Dissolved Solids | |
Truckee River | From Lockwood to Derby Dam | Nitrogen (Total), Phosphorus (Total), Total Dissolved Solids | |
Truckee River | From Derby Dam to Wadsworth | Nitrogen (Total), Phosphorus (Total), Total Dissolved Solids | |
Virgin River | From the Nevada-Arizona state line to Mesquite | Boron | |
Virgin River | From Mesquite to river mouth at Lake Mead | Boron | |
Walker Lake | The entire lake | Total Dissolved Solids | |
Walker River | From the confluence of Walker River, West and East Forks to the boundary of the Walker River Indian Reservation | Total Suspended Solids (TSS) | |
Walker River, East Fork | From the Walker River, East Fork at the Nevada-California state line to Bridge B-1475 | Total Suspended Solids (TSS) | |
Walker River, East Fork | From Bridge B-1475 to its confluence with the Walker River, West Fork | Total Suspended Solids (TSS) |