readNWISgwl: Groundwater level measurements retrieval from USGS (NWIS)

View source: R/readNWISunit.R

readNWISgwlR Documentation

Groundwater level measurements retrieval from USGS (NWIS)


Reads groundwater level measurements from NWISweb. Mixed date/times come back from the service depending on the year that the data was collected. See for details about groundwater. By default the returned dates are converted to date objects, unless convertType is specified as FALSE. Sites with non-standard date formats (i.e. lacking a day) can be affected (see examples). See for more information.


  startDate = "",
  endDate = "",
  parameterCd = NA,
  convertType = TRUE,
  tz = "UTC"



character USGS site number (or multiple sites). This is usually an 8 digit number


character starting date for data retrieval in the form YYYY-MM-DD. Default is "" which indicates retrieval for the earliest possible record.


character ending date for data retrieval in the form YYYY-MM-DD. Default is "" which indicates retrieval for the latest possible record.


character USGS parameter code. This is usually an 5 digit number. Default is "".


logical, defaults to TRUE. If TRUE, the function will convert the data to dates, datetimes, numerics based on a standard algorithm. If false, everything is returned as a character


character to set timezone attribute of dateTime. Default is "UTC", and converts the date times to UTC, properly accounting for daylight savings times based on the data's provided tz_cd column. Possible values to provide are "America/New_York", "America/Chicago", "America/Denver", "America/Los_Angeles", "America/Anchorage", as well as the following which do not use daylight savings time: "America/Honolulu", "America/Jamaica", "America/Managua", "America/Phoenix", and "America/Metlakatla". See also OlsonNames() for more information on time zones.


A data frame with the following columns:

Name Type Description
agency_cd character The NWIS code for the agency reporting the data
site_no character The USGS site number
site_tp_cd character Site type code
lev_dt Date Date level measured
lev_tm character Time level measured
lev_tz_cd character Time datum
lev_va numeric Water level value in feet below land surface
sl_lev_va numeric Water level value in feet above specific vertical datum
lev_status_cd character The status of the site at the time the water level was measured
lev_agency_cd character The agency code of the person measuring the water level

There are also several useful attributes attached to the data frame:

Name Type Description
url character The url used to generate the data
queryTime POSIXct The time the data was returned
comment character Header comments from the RDB file
siteInfo data.frame A data frame containing information on the requested sites

See Also

constructNWISURL, importRDB1


site_id <- "434400121275801"

data <- readNWISgwl(site_id)
sites <- c("434400121275801", "375907091432201")
data2 <- readNWISgwl(site_id, "", "")
data3 <- readNWISgwl("420125073193001", "", "")
# handling of data where date has no day
data4 <- readNWISgwl("425957088141001", startDate = "1980-01-01")

data5 <- readNWISgwl("263819081585801", parameterCd = "72019")

dataRetrieval documentation built on Nov. 24, 2022, 1:06 a.m.