North Fork Maquoketa River IA 01-NMQ-88

Assessment Comments

290120 (21IOWA/DNR) just north of Maquoketa. WQ study by DNR/LTRMP in May & July 1996 at two locations.

Basis for Assessment

No violations of water quality criteria for either conventional or toxic pollutants in the 24 samples collected monthly over the two-year period.   A summary of water quality in the N.Fk.  Maquoketa was prepared by DNR/EPD in 1997 as part of a multi-agency study on water quality of the Maquoketa River watershed.   This study concluded that the water quality of the N.Fk.  is typical of streams draining the Southern Iowa Rolling Loess Prairies ecoregion and that the primary sources of sediment and nutrients delivered to the Mississippi R by the Maquoketa River were due to relatively erosive subbasins in the lower Maquoketa River basin.   Runoff sampling was conducted in May and July 1996 by DNR/LTRMP (Bellevue) staff at 24 sites along the Maquoketa River and its major tributaries.  Based on results of this monitoring, three subwatersheds of the N.Fk.  were (Farmers, Lytle, and Whitewater creeks) were identified as contributing excessive amounts of sediment and nutrients to the Maquoketa River.   This information was used to generate support for watershed projects designed to reduce levels of sediment and nutrient delivery.   This effort is being coordinated by the Maquoketa River Alliance and the Limestone Bluffs Resource Conservation and Development Area Office at Maquoketa.   NRCS, Farm Bureau, county Extension staff, and landownwers are cooperating in this effort.   Despite results of the special runoff studies conducted by the DNR/LTRMP, continued to assess the support of the aquatic life uses of this reach of the N.Fk.  as FST.   Although this stream has relatively high levels of suspended solids and nutrients, follow-up monitoring is needed to determine the status of the aquatic communities of this river reach and to determine whether the Class B(WW) aquatic life uses are impaired.