Flow levels on the Ipswich River were at critically low levels from mid summer through mid December. They have now recovered to ecologically safe levels.
South Middleton Gage:
Flows at this gauge, maintained by the U.S. Geological Survey (USGS), were also been below the ecological protection flow of 19 cubic feet per second (cfs) from August through December of 2013. This level was determined in a USGS study to be a safe level for fish and other aquatic organisms in this part of the river. The lowest flow on record for this site was 0.07 cfs in the summer of 1997.
The ecological protection flow at the USGS Ipswich gage was determined to be 53cfs. Flows at this gage have also been below this level since August. The lowest flow on record for this site is 0.86 cfs in 2010.
LOW FLOWS EXPLAINED:
Low flows are linked to the loss of river dependent fish such as brook trout and it can make shallow stretches difficult for paddling. Low flows dry up critical habitat for fish and other aquatic organisms, cause water temperatures to rise and lower dissolved oxygen levels.
Another USGS study determined that groundwater withdrawals are mainly responsible for summer low flows, especially in the upper watershed. This is important because critical stream habitat becomes unavailable for fish and other aquatic organisms.
Riffle zones that mix oxygen in the water dry up and stream bank habitat cannot be reached (a riffle is a relatively shallow and usually rocky length of stream over which the stream flows at higher velocity and higher turbulence than it normally does in comparison to a pool). When flows are low, water temperatures rise more rapidly and dissolved oxygen levels decline. Prolonged low flows can lead to fish kills and loss of diversity among aquatic insects. Most fish require dissolved oxygen levels of 5 parts per million (ppm) or greater. We know from our volunteer water quality monitoring that dissolved oxygen levels were below this level at over half of our monitoring sites beginning at the end of July.
Flows in the river are affected by municipal water supplies located in Wilmington, North Reading, Lynn, Lynnfield, Danvers, Salem, Beverly, Peabody and by private wells at locations such as the Thomson Country Club in North Reading.
This map of real-time streamflow compares to historical streamflow for each day of the year in Massachusetts.
We can all do our part to conserve water and improve flows in the river and restore more natural conditions and diversity to the Ipswich River. Do you know where your water comes from? Learn more about your town’s drinking water sources.
Please explore our SaveWaterNorthShore.org website for more tips and information on saving water indoors and outdoors.
Our volunteer RiverWatch monitoring program assesses the health of the Ipswich River. Volunteers collect data monthly from March-December on weather conditions, rain in the last 48 hours, water color, odor and clarity, water temperature, dissolved oxygen, velocity, depth and conductivity. Measurements are taken at 31 sites throughout the watershed. Monitoring reports are available here.
2013 Monitoring Results
Note: In the above map, click on an individual site and a series of pop ups will contain the following links:
- Site Data: You can download the data for that particular monitoring site as an excel spreadsheet.
- Monthly Results: You can download a set of graphs summarizing all site data for each month. See how current and past data compare to water quality standards.
- Click away from a site and only the summary graphs will be available.