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

Objective 1

Understand sources, sinks, and spatial/ temporal patterns associated with nutrients and metals in UCFR main channel and relevant tributaries.

Working Hypotheses

  • 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.

Objective 2

Understand how floodplain land uses interact with irrigation practices, tributaries and legacy mining influences to affect nutrient enrichment in the UCFR.

Working Hypotheses

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.

Recommended Activities

  • 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.

Objective 3

Understand sources of, and controls over, N concentrations and loads associated with the Lost Creek Dutchman Complex.

Working Hypotheses

  • 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

Objective 4

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

 

UCFWG Members working on Water Quality & Biogeochemistry