Salmonid Restoration Federation

Monitoring FAQs

What information do you hope to gather through the Low-Flow Monitoring Project?

To address the low-flow problem in Redwood Creek, SRF began a study in 2015 with these objectives:

  1. Quantify summer/fall stream discharges at a suite of main channel and tributary sites;
  2. Evaluate possible causes of unexpected flow variations (e.g., decreasing discharge with increasing drainage area); 
  3. Identify and rank sub-watersheds that may be impacted by water diversions and therefore benefit from forbearance agreements;
  4. Recommend means to streamline future monitoring.
What kind of data do you collect at your monitoring sites?

We collect streamflow, water and air temperature, dissolved oxygen, fish observations, and water levels.

How many monitoring sites do you collect data from?

We collect data from 10 monitoring sites throughout the Redwood Creek Watershed.

How often do you collect data at the monitoring sites?

Our Monitoring Coordinator, Katrina Nystrom, collects data every-other week during the monitoring season, which is typically May through November. SRF has also deployed data loggers that, once deployed into the river, collect measurements every 15 minutes.

What is a ‘logger?’

A logger is an instrument we use to collect data about the level of the water. We also use it to collect stream temperature. We deploy the loggers into the river during the monitoring season and download the data to a computer once a month.

How do you know how much the river is flowing?

SRF collects flow measurements using a current meter, Parshall Flume, or bucket-and-stopwatch method, depending on how much water is flowing.

With adequate flow depth, a spinning cup-type current meter or electromagnetic device will be used to take velocity measurements across the gaging cross section.

When depths are too shallow to use a velocity meter, either a Parshall Flume or the bucket-and-stopwatch method will be used. When properly installed into the channel bed, the flume discharge is computed from the depth of flow using a rating formula. With the bucket-and-stopwatch method, flow is concentrated so it pours into a bucket, the filling of which is timed.