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Ipswich-Parker Suburban WATershed CHannel |
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Flow information is updated daily from the USGS gages in the Ipswich R. @Ipswich, Ipswich R. @ Middleton, and Parker R. @ Byfield. Data are retrieved from the USGS web site at midnight each day. The previous days flow observations are averaged and then compared against long term daily flow statistics determined from USGS historical data.
The following ratings are used:
Record Low = lowest flow ever recorded on this date.
Record High = highest flow ever recorded on this date.
Critically Low = below the 10th percentile of historical flow for this date. Flow drops this low on average once every 10 years.
Extremely High = above the 90th percentile fo historical flow for this date. Flow is above this level on average once every 10 years.
Below Median = flow is below the 50th percentile, but not critically low.
Above Median = flow is above the 50th percentile, but not extremely high.
Fish habitat quality is assessed based on flow levels only. Other factors that are important in determining fish habitat quality, such as dissolve oxygen levels, are not included in this rating (though see D.O. information below).
The assessment is based on a USGS study recently published regarding the level of flow needed to maintain fish habitat quality in the Ipswich R. In this study researchers concluded that a flow of 0.42 cubic feet per second per square mile (CFSM) is required for adequate fish habitat. Based on this amount, we rate fish habitat in the Ipswich R. and Parker R. using data from the USGS stream discharge gages in those watersheds.
For the Ipswich R. we use the gage located at Ipswich
and for the the Parker R. we use the gage at Byfield. Although the USGS study
was conducted in the Ipswich R. we assume that similar flows are needed in the
Parker to maintain adequate fish habitat. Flow levels below the
criteria result in a poor rating, and otherwise fish habitat is rated as acceptable.
The flow criteria are as follows:
Ipswich@Ipswich gage = 52.5 cfs (using the watershed area of 125 sq. mi.)
Parker@Byfield gage = 9.0 cfs (using the watershed area of 21.3 sq. mi.)
Click here for a link to the USGS report on fish habitat quality.
Water quality is updated twice daily from one location in the upper Ipswich R.
watershed where the Ipswich flows between Reading and North Reading.
Water quality is measured at other sites as well
but these are currently not telemetered. Water quality is based on the
water quality standards developed
by the state for streams and rivers. The Ipswich R. is rated a warm water fishery. Based on these standards water quality is rated as follows:
Temperature > 28.3 Celcius = substandard
Dissolved Oxygen < 5 mg/l = substandard
pH < 6.5 = substandard
For a map of all water quality and flow measurement sites click here.