This data release provides mean annual flow and climate variables based on the Northern Hemisphere water year (October 1 to September 30) and several watershed properties are provided for A) 161 USGS reference watersheds smaller than 500 square kilometers that are also part of the Catchment attributes for large-sample studies (CAMELS) dataset (Addor et al., 2017) and B) 924 USGS non-reference watersheds smaller than 500 square kilometers, C) mean annual flow and climate variables for 12 Colorado Division of Water Resources (CDWR) gages. For each climatic variable, mean annual values were derived from watershed average annual values.

The columns of the datasets are as follows:

A) "USGS_CAMELS_ref.csv"

GAGE_ID = USGS gage station number
Q_mm = total water year water yield from USGS NWIS
P_PRISM_mm = watershed averaged total water year precipitation from PRISM- Daly, 2013
PET_gridMET_mm = watershed averaged total water year potential evapotranspiration from gridMET - Abatzoglou, 2013
drain_SQKM = USGS watershed drainage area - Falcone, 2011
elevation_m = USGS watershed mean elevation - Falcone, 2011
SP = watershed averaged January 1 to July 1 snow persistence - Hammond et al., 2017
p_camels_mm = watershed averaged total water year precipitation from CAMELS- Addor et al., 2017
pet_camels_mm = watershed averaged total water year potential evapotranspiration from CAMELS- Addor et al., 2017
q_camels_mm = total water year water yield from from CAMELS- Addor et al., 2017
PETdivP_PRISM_gridMET = ratio of PET_gridMET_mm to P_PRISM_mm
PETdivP_camels = ratio of pet_camels_mm to p_camels_mm
PETdivP_camels_PRISM = ratio of pet_camels_mm to P_PRISM_mm
PETdivP_gridMET_camels = ratio of PET_gridMET_mm to p_camels_mm
AET_PRISM = P_PRISM_mm minus Q_mm
AET_camels = p_camels_mm minus q_camels_mm
AETdivP_PRISM = ratio of AET_PRISM to P_PRISM_mm
AETdivP_camels = ratio of AET_camels to p_camels_mm
PETdif = (PET_gridMET_mm-PET_camels_mm)/PET_gridMET_mm
DEVNLCD06 = Watershed percent "developed" (urban), 2006 era. Sum of classes 21, 22, 23, and 24 - Falcone, 2011
FORESTNLCD06 = Watershed percent "forest", 2006 era. Sum of classes 41, 42, and 43 - Falcone, 2011
PLANTNLCD06 = Watershed percent "planted/cultivated", 2006 era. Sum of classes 81 and 82 - Falcone, 2011
SHRUBNLCD06 = Watershed percent Shrubland (class 52) - Falcone, 2011
GRASSNLCD06 = Watershed percent Herbaceous (class 71) - Falcone, 2011

B) "USGS_nonref.csv"

GAGE_ID = USGS gage station number
Q_mm = total water year water yield from USGS NWIS
P_PRISM_mm = watershed averaged total water year precipitation - PRISM, Daly, 2013
PET_gridMET_mm = watershed averaged total water year potential evapotranspiration - gridMET - Abatzoglou, 2013
drain_SQKM = USGS watershed drainage area - Falcone, 2011
elevation_m = USGS watershed mean elevation - Falcone, 2011
SP = watershed averaged January 1 to July 1 snow persistence -Hammond et al., 2017
PETdivP = ratio of PET_gridMET_mm to P_PRISM_mm
AET = P_PRISM_mm minus Q_mm
AETdivP = ratio of AET to P_PRISM_mm
DEVNLCD06 = Watershed percent "developed", 2006 era. Sum of classes 21, 22, 23, and 24 - Falcone, 2011
FORESTNLCD06 = Watershed percent "forest", 2006 era. Sum of classes 41, 42, and 43 - Falcone, 2011
PLANTNLCD06 = Watershed percent "planted/cultivated", 2006 era. Sum of classes 81 and 82 - Falcone, 2011
SHRUBNLCD06 = Watershed percent Shrubland (class 52) - Falcone, 2011
GRASSNLCD06 = Watershed percent Herbaceous (class 71) - Falcone, 2011

C) "CDWR_Sangres.csv"

GAGE_ID = CDWR gage ID
Name = CDWR gaging station name
Area_km2 = CDWR watershed drainage area - Colorado Information Marketplace (https://data.colorado.gov/Water/Current-Surface-Water-Conditions-in-Colorado/)
P_PRISM_mm = watershed averaged total water year precipitation - PRISM, Daly, 2013
SP = watershed averaged January 1 to July 1 snow persistence - Hammond et al., 2017
PET_gridMET_mm = watershed averaged total water year potential evapotranspiration - gridMET - Abatzoglou, 2013
Q_mm = total water year water yield - Colorado Information Marketplace

-Abatzoglou, J. T. (2013). Development of gridded surface meteorological data for ecological applications and modelling. International Journal of Climatology, 33(1), 121–131.
-N. Addor, A. Newman, M. Mizukami, and M. P. Clark, 2017. Catchment attributes for large-sample studies. Boulder, CO: UCAR/NCAR.
-Daly, C. (2013). Descriptions of PRISM spatial climate datasets for the conterminous United States (PRISM Doc., 14 p.).
-Falcone, J. A. (2011). GAGES-II: Geospatial attributes of gages for evaluating streamflow. Reston, VA: U.S. Geological Survey.
-Hammond, J. C., F. A. Saavedra, S. K. Kampf (2017). MODIS MOD10A2 derived snow persistence and no data index for the western U.S., HydroShare.