Nutrient Enrichment & Biogeochemistry of UCFR Waters
Improve knowledge of water quality and biogeochemistry effects on aquatic species diversity and food web productivity along the UCFR.
Related NRDP Restoration Plan Limiting Factors:
- Water quality, including elevated nutrients (resulting in algal blooms)
- Agriculture/irrigation practices (grazing, haying, etc.), storm-water and wastewater treatment
- Metals contaminated floodplain, stream banks, and channel bed
- Water temperature
Understand sources, sinks, and spatial/ temporal patterns associated with nutrients and metals in UCFR main channel and relevant tributaries.
- Combination of waste water treatment, livestock grazing, agriculture and related fertilization, dewatering of wetlands, metals effects on nutrient chemistry and pathways, and lack of vegetation negatively impact river processes.
- High nitrate arriving from Lost Creek (winter) and Racetrack Creek (summer) contributes to main channel algal blooms downstream when sufficient phosphorus becomes available from Flint Creek or land use practices.
- Nitrates from UCFR combined with P from Reach B, low flows, lack of floodplain connectivity, high water temps, and long periods of available light, support unusually high algal growth in some reaches of the CFR.
- Maintain and extend water monitoring programs for the UCFR and select tributaries. Response variables: temperature, DO, specific electrical conductivity, N (nitrate, ammonium, TN), P (soluable reactive P, TP), DOC, metals (Cu, Zn, Cd, Pb, As). Consider adding groundwater monitoring (LCDC network, other).
- Identify, map and characterize wastewater treatment plants in the UCFR including material loading behaviors over space and time
- Fine scale measures of nutrient concentrations in main channel and tributary and irrigation return contributions
- Generate N, P and metals budgets in Reach A to assess net changes in material loads. Combine nutrient and metals concentrations with river flow data to determine successive solute loads. Employ automated nitrate sensors and autosamplers to quantify diel fluctuations and address sampling implications. Calculate net changes in loads within reaches to generate uptake and production metrics.
Understand how floodplain land uses interact with irrigation practices, tributaries and legacy mining influences to affect nutrient enrichment in the UCFR.
Combination of waste water treatment, livestock grazing, agriculture and related fertilization, dewatering of wetlands, metals effects on nutrient chemistry and pathways, and lack of vegetation negatively impact river processes.
- Generate a spatially-explicit model of nutrient and metals sources to the floodplain and link it to the main river channel to assess how land use leads to river enrichment.
- Use a socioecological approach to understand floodplain residents’ agricultural and land use practices.
Understand sources of, and controls over, N concentrations and loads associated with the Lost Creek Dutchman Complex.
- N loads increase substantially as Lost Creek flows across the Dutchman complex. Nitrate concentrations in groundwater are low compared to stream water while reduced N (ammonium) concentrations are greatly elevated in groundwater.
- Nitrification at the groundwater-surface water interface greatly increases N loads to the UCFR at the confluence with the main channel.
- Sources of reduced N to the LCDC are unknown, but likely related to inputs from compormised secondary wastewater holding ponds and from mineralization of wetland soils promoted by dewatering
- Determine hydrologic linkages among surface and groundwater components of the Lost Creek Dutchman Complex by generating a flow net and employing MODFLOW/MODPATH modeling.
- Maintain and extend nutrient monitoring of surface and groundwater network to characterize nutrient and metal content of LCDC waters.
- Use microcosm assays to address N production from peatland and other soils that may serve as N sources to the LCDC complex.
- Use nitrate stable isotope composition (i.e., 15N and 18O ) to assess nitrification and denitrification and address isotope potential to track N sources.
- Work with operators to understand the magnitude and timing of wastewater loading to secondary ponds on the LCDC and to the terrestrial landscape during the growing season. Address implications of operational upgrades scheduled for the WWTP.
Determine how biological processes respond to and alter water quality and material loads over seasonal time frames among and within Reaches A, B and C
No Current Working Hypotheses
- Deploy automated oxygen sensors and use light, depth and temperature to generate whole-reach measures of primary production and ecosystem respiration.
- Link metabolic measures to changes in nutrient and metals loads to address in-stream biological influences.
- Compile relevant literature on Warm Springs Ponds in electronic format within UCFWG information management platform and synthesize current understanding of pond behavior.
- Evaluate potential to modify Warm Springs Ponds management to improve river conditions and downstream restoration outcomes.
UCFWG Members working on Water Quality & Biogeochemistry