DOI: 10.5281/zenodo.15531298
title: Dataset: Water and Nutrient Mass Balances of Upper Klamath Lake, WY 1992-2023.

description: Monthly and annual water and nutrient (total phosphorus and total nitrogen) mass balances were developed for Upper Klamath Lake (UKL) over water year (WY) 1992-2023. UKL is a shallow, hyper-eutrophic lake located in south-central Oregon, USA. The water and nutrient balances were computed using available flow and water quality sampling data for various inflow sources and the lake outflow. Changes in water and nutrient mass storage were computed from measured lake surface elevations using elevation-area-volume curves based on the lake bathymetry, and biweekly water quality sampling. The net retention of nutrients were computed by difference from the other measured or estimated inflow, outflow, and storage terms. 

The data sources and methodologies used to generate this dataset are described in the following report:



Walker, Jeffrey D, & Kann, Jacob. (2022). Water and Nutrient Balances of Upper Klamath Lake, Water Years 1992–2018. Zenodo. https://doi.org/10.5281/zenodo.6607800


This repository contains the following files:



ukl-mb-mon.csv: monthly flows, loads, and flow-weighted mean (FWM) concentrations of total phosphorus (TP) and total nitrogen (TN) for each mass balance term

ukl-mb-wyr.csv: annual flows, loads, and flow-weighted mean (FWM) concentrations of TP and TN for each mass balance term based on water years (WY = Oct 1 - Sep 30; e.g., WY 2018 = Oct 1, 2017 - Sep 30, 2018)


Mass balance terms include:



tribs_7mile_dike: Sevenmile Canal @ Dike Road (outlet to Agency Lake)

tribs_wood_dike: Wood River @ Dike Road (outlet to Agency Lake)

tribs_wood_dike-weed: Wood River between Dike and Weed Roads

tribs_wood_weed: Wood River @ Weed Road

tribs_sprague: Sprague River

tribs_williamson-sprague: Williamson River excluding Sprague River basin

tribs_williamson: Williamson River (outlet to Upper Klamath Lake)

tribs_total: Total gauged tributaries (Sevenmile Canal + Wood River + Williamson River)

pumped_alr: Pumped inflows from Agency Lake Ranch

pumped_wrdp: Pumped inflows from Williamson River Delta Preserve (Tulana + Goose Bay)

pumped_ungauged: Pumped inflows from other ungauged agricultural areas

pumped_total: Total pumped inflows (ALR + WRDP + Ungauged Pumped Areas)

ungauged: Ungauged drainage basins

total_external: Total external inflows (Gauged Tributaries + Ungauged Basins + Pumped Areas)

precip: Precipitation (total atmospheric deposition for nutrient loads)

evap: Evaporation

net_inflow: Net inflow (Total External Inflows + Precipitation - Evaporation)

outflow: Lake outflow

storage: Lake mean storage (Upper Klamath and Agency Lakes)

dstorage: Change in lake storage

retention: Net retention

anthro: Anthropogenic inflows

background: Background inflows


See Table D1 (Appendix D) of Walker and Kann (2022) for equations to compute flows and loads of terms derived from other directly measured or estimated terms.

File columns:



wyear: Water year (Oct 1 - Sep 30; e.g., WY 2018 = Oct 1, 2017 - Sep 30, 2018)

date: Date on the first day of each month (monthly dataset only)

term: Mass balance term (see above)

param: Water quality parameter (tp or tn)

flow_hm3: Flow or storage volume (hm^3 = 1e6 m^3 = 0.81071 kacre-ft)

load_kg: Load or storage mass (kg = 1e-3 metric tonne or mton)

conc_ppb: Concentration (ppb = ug/L = 1e3 mg/L)

area_km2: Drainage/surface area associated with each term (km2)

runoff_m: Unit-area runoff (m) equal to flow_hm3 divided by area_km2

export_kg_km2: Nutrient export rate (kg/km2) equal to load_kg divided by area_km2