This week's rain doesn't help high nitrate levels and the watering ban. Here's why.
This week's rain doesn't help high nitrate levels and the watering ban. Here's why.
BOWMAN vlog EIGHT NEWS. IOWA’S NEWS LEADER. INTERESTING TO SEE THE SCIENCE BEHIND IT ALL. NOW, SOME OF US HAVE BEEN WONDERING HOW ALL THE RAIN THIS WEEK COULD IMPACT THE SITUATION. THAT’S RIGHT. STORM TEAM EIGHT METEOROLOGIST ZANE SATRE JOINS US NOW TO EXPLAIN HOW STORMS LIKE WE’VE SEEN CAN IMPACT THOSE NITRATE LEVELS. ZANE. YEAH. JODI. AURORA. LOTS OF RAIN FELL YESTERDAY INTO TODAY. OR ALTHOUGH YOU CAN TELL BY THE MAP, THE HEAVIEST OF IT WASN’T NECESSARILY IN THE DES MOINES OR RACCOON RIVER BASINS UPSTREAM OF THE METRO. MANY, THOUGH, HAVE ASKED, DOES THAT HELP? DOES THAT RAIN HELP OUR SITUATION? NOT REALLY. ACCORDING TO CENTRAL IOWA WATER WORKS, DURING HEAVY RAINFALL, NITRATE LEVELS CAN BRIEFLY DROP DUE TO THE EXTRA WATER KIND OF DILUTING THEM. BUT AFTER THAT, THE NITRATE LEVELS CAN CLIMB EVEN HIGHER. THIS HAPPENS BECAUSE THE RAIN THAT FELL UPSTREAM BEGINS TO RUN INTO THE RIVERS FROM FARM FIELDS, THROUGH DRAINAGE TILE AND SO ON. YOU CAN ACTUALLY SEE THAT EFFECT HERE. THIS CHART FROM THE IOWA WATER QUALITY INFORMATION SYSTEM SHOWS NITRATE LEVELS MEASURED BY A GAUGE ON THE RACCOON RIVER UPSTREAM OF DES MOINES NEAR VAN METER. SINCE FEBRUARY, YOU CAN SEE THE LEVELS CLIMB ONCE WE GET OUT OF THIS IS FEBRUARY. ONCE WE GET OUT OF WINTER AND INTO THE SPRING SEASON, AS RAINFALL INCREASES AND THAT DRIVES MORE RUNOFF. MOST YEARS FOLLOW THIS SORT OF TREND. EVERY ONE OF THESE LITTLE SPIKES IN NITRATE THAT YOU SEE FOLLOWS A WIDESPREAD SOAKING RAIN. WE CHECKED IF THIS YEAR TRENDS LIKE PREVIOUS YEARS, THEN NITRATE LEVELS WILL STEADILY DROP ONCE WE GET INTO JULY AND THEN INTO AUGUST. BUT IN THE SHORT TERM, RAINFALL IS
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This week's rain doesn't help high nitrate levels and the watering ban. Here's why.
Lots of rain fell in the last 24 hours, though the heaviest wasn't in the Des Moines or Raccoon River basins upstream of the metro area.The rain likely will extend the lawn watering ban for residents and businesses, according to Central Iowa Water Works.During heavy rainfall, nitrate levels can briefly drop due to extra water diluting the compound. But after that, nitrate levels can climb even higher.This happens because the rain that fell upstream begins to run off into the rivers — from farm fields, through drainage tile and other sources.According to Iowa Water Quality Information Systems, nitrate levels rising is measured by a gauge on the Raccoon River upstream of Des Moines near Van Meter.Levels climb through the spring as rainfall increases and drives more runoff.Most years follow this pattern. Nitrate levels spike following a widespread soaking rain.If this year follows previous years, nitrate levels will steadily drop from July into August.Recent coverage of central Iowa water issuesCentral Iowa officials ban lawn watering to avoid potential 'water crisis'What are nitrates in drinking water and why Iowa officials are watching closelyLIST: Which Iowans are included in the ban on lawn watering?Des Moines shuts down spraygrounds as central Iowa cities work to conserve waterClive residents respond to lawn watering ban amid high nitrate levelsCentral Iowa landscaping businesses adapt to lawn watering banLawn watering ban still in place for more than 600,000 central Iowans; water usage drops by 30%Des Moines Water Works CEO links nitrate issue to farm fertilizers Communities can reopen splash pads and spraygrounds, Central Iowa Water Works says Get the Facts: How much water do West Des Moines data centers actually use?Splash pads turn back on one week later after new guidance from CIWWCentral Iowa water officials squash rumors that drinking water is unsafeCentral Iowa water quality experts say at-home nitrate test kits are unreliableMore Iowans considering at-home water treatment systems amid water quality concernsvlog Investigates: Water demand shot up day before lawn watering ban began, data shows
DES MOINES, Iowa —
Lots of rain fell in the last 24 hours, though the heaviest wasn't in the Des Moines or Raccoon River basins upstream of the metro area.
The rain likely will extend the lawn watering ban for residents and businesses, according to Central Iowa Water Works.
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During heavy rainfall, nitrate levels can briefly drop due to extra water diluting the compound. But after that, nitrate levels can climb even higher.
This happens because the rain that fell upstream begins to run off into the rivers — from farm fields, through drainage tile and other sources.
According to Iowa Water Quality Information Systems, nitrate levels rising is measured by a gauge on the Raccoon River upstream of Des Moines near Van Meter.
Levels climb through the spring as rainfall increases and drives more runoff.
Most years follow this pattern. Nitrate levels spike following a widespread soaking rain.
If this year follows previous years, nitrate levels will steadily drop from July into August.
Recent coverage of central Iowa water issues
- Central Iowa officials ban lawn watering to avoid potential 'water crisis'
- What are nitrates in drinking water and why Iowa officials are watching closely
- LIST: Which Iowans are included in the ban on lawn watering?
- Des Moines shuts down spraygrounds as central Iowa cities work to conserve water
- Clive residents respond to lawn watering ban amid high nitrate levels
- Central Iowa landscaping businesses adapt to lawn watering ban
- Lawn watering ban still in place for more than 600,000 central Iowans; water usage drops by 30%
- Des Moines Water Works CEO links nitrate issue to farm fertilizers
- Communities can reopen splash pads and spraygrounds, Central Iowa Water Works says
- Get the Facts: How much water do West Des Moines data centers actually use?
- Splash pads turn back on one week later after new guidance from CIWW
- Central Iowa water officials squash rumors that drinking water is unsafe
- Central Iowa water quality experts say at-home nitrate test kits are unreliable
- More Iowans considering at-home water treatment systems amid water quality concerns
- vlog Investigates: Water demand shot up day before lawn watering ban began, data shows