Story County stream monitoring, 2023
Daniel Haug, Prairie Rivers of Iowa
2024-01-04
Introduction
Prairie Rivers of Iowa and its partners completed a fourth year of a water monitoring project in Story County. Updated through December.
Keigley Branch was partially frozen on December 20.
# 2023-01-31 Started over with 2023 data
# Import csv file provided by City of Ames
# Skip unneeded columns for tidy format
library(tidyverse)
library(readr)
library(lubridate)
ameslab2023 <- read_csv("data/ameslab2023.csv", na = "NULL",
col_types = cols(CollectionDate = col_date(format = "%m/%d/%Y"),
CollectionTime = col_skip(), Comment = col_skip(),
MRL = col_skip(), LabID = col_integer(),
Method = col_skip(), Note = col_skip(),
Symbol = col_skip(), Unit = col_skip()))
# renames a column for clarity
ameslab2023 <- rename(ameslab2023, site = Description)
View(ameslab2023)
# Tidy the data, so each analyte is in a column
ames_tidy<- ameslab2023 %>%
pivot_wider( names_from = Analyte, values_from = Result) %>%
mutate(Year = year(CollectionDate), Month = month(CollectionDate, label = TRUE),
Day = day(CollectionDate))
# Adds a column from a lookup table to allow ordering sites from upstream to downstream
library(readr)
lookup_US_DS <- read_csv("data/lookup_US_DS.csv")
ames_tidy <- left_join(ames_tidy, lookup_US_DS, by = "site")If you see a car stopped by a bridge in Story County with someone pulling up a milk jug of water on a rope, there’s a good chance it’s me or volunteer Rick Dietz, doing our monthly monitoring route. We collect water samples from 10 sites, and City of Ames staff cover another five. Laboratory Services for City of Ames Water and Pollution Control tests the samples for nitrate, total phosphorus, total suspended solids, and E. coli bacteria.
Weather and flow conditions
December 20: Water levels were low, Story County was in severe drought. Seven sites could not be sampled due to thick ice or lack of flowing water.
November 15. Water levels were low, parts of Story County were in moderate drought. Ioway Creek, College Creek, Clear Creek, and Worrell Creek were not flowing.
October 18. Water levels were low, parts of Story County were in moderate drought. College Creek, Clear Creek, and Worrell Creek were not flowing.
September 20. Scattered showers the previous day dropped up to 5 inches in the southern part of the county. Soils have been very dry so some rural streams did not rise much in response to rain.
August 16. Water levels were normal following light rain earlier in the week and heavy rain the previous week.
July 26. Continued dry conditions. Most streams were low. College Creek and Worrell Creek were not flowing. Ioway Creek could not be sampled because of road closure.
June 21. Story County was was abnormally dry but it had rained on June 17 and water levels were normal.
May 17. Water levels in the South Skunk River were normal.
April 19. Water testing was done when weather was drier than normal for spring.
March 22. While March included several episodes of snow, the air temperature was warm and there had only been trace rain when we sampled. Water levels were normal for this time of year.
February 15. Rivers were rising at the time of sampling and very turbid, affected both by snowmelt and rain (0.9 inches the previous day). Smaller streams like West Indian Creek were near bankfull and the South Skunk River at Sleepy Hollow Access was above the red line on the canoe access (corresponding to 600 cfs).
January 18. The weather was warm enough that most streams had open water, but samples could not be collected from Keigley Branch, Worrell Creek, or Ioway Creek.
E. coli bacteria
The support of a certified lab provides a backstop for volunteer monitoring and allows us to make direct comparisons with laboratory data from DNR and other agencies. It also allows us to test for E. coli bacteria, an indicator of fecal contamination from human waste, livestock, pets, or wildlife.
