We can keep track of flow levels on the Ipswich River by monitoring two USGS graphs that show flows measured at two real-time streamflow gages on the Ipswich River near the South Middleton and Willowdale Dams (Hamilton/Ipswich). This is a good way to assess whether flows are above or below ecological protection levels (is there enough water for fish and other aquatic organisms) and whether there is enough water to paddle certain stretches of river that are flow dependent.
Ipswich River Near Boston St., South Middleton
Based on USGS study, summer flow rates at or above 19 cfs at this gage can be considered ecologically safe. Flows above this level are generally suitable for navigating the mainstem of the river through North Reading.
Ipswich River Near Willowdale Dam, Ipswich
Based on a USGS study, summer flow rates at or above 53 cfs at this gage can be considered ecologically safe. Flows above this level are generally suitable for navigating the mainstem of the river from Winthrop St. in Ipswich to the Ipswich River Watershed Association Riverbend headquarters in Ipswich.
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.
The ecological protection flow level at the South Middleton gauge, maintained by the U.S. Geological Survey (USGS), is 19 cubic feet per second (cfs) while at the Ipswich gage location, it is 53 cfs. These levels were determined in a USGS study to be a safe threshold for fish and other aquatic organisms. During 2013, flows fell below these levels from mid-August until the end of November. These long periods of low flows occur annually and have a long-term impact on the ability of the river to support a diverse community of organisms.
A USGS study determined that groundwater withdrawals are mainly responsible for summer low flows, especially in the upper watershed. 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.
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. Our volunteer water quality monitors consistently observe dissolved oxygen levels below this level during the summer when flows are lowest. Our macroinvertebrate sampling has recorded a high proportion of organisms that can tolerate low water quality and fewer sensitive organisms than would be expected for a healthy river.
We can all do our part to conserve water, improve flows and restore more natural conditions and biodiversity 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.
WATER QUALITY MONITORING
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.
2014 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.