Water Protection Activities in Washtenaw County

B7 - Plan 7: River Raisin Watershed Management Plan
(Phase 1)
Plan Date: April 2006
The Washtenaw County portion of the River Raisin Watershed
exists in the South-central and Southwestern part of the
County. It has the second largest drainage area in the county,
ranking behind the Huron. The watershed starts in the north at
Sharon, Freedom, Lodi, and Pittsfield townships and extends
south into the townships of Manchester, Bridgewater, Saline
and York. Additionally, portions of Manchester Village, and
Saline and Milan cities also drain to the River Raisin
Watershed. The Watershed Starts to the west of Washtenaw
County in Hillsdale County and runs eastward through Jackson
County into Washtenaw. South of Washtenaw County the
River Raisin and the watershed areas that feed it continue on
through Lenawee and Monroe County and eventually drain to
Lake Erie. The Raisin Watershed is approximately 1074 square
miles and extends into Ohio in its southern reaches. A TMDL
for pathogens and untreated sewage discharge exists in the
Saline River, in York Township.
The River Raisin Watershed Management Plan - Phase 1 is a
University of Michigan School of Natural Resources and
Environment (SNRE) student project that was initiated in
cooperation with the River Raisin Watershed Council
(RRWC). It is part of the $277,000 Section 319 grant to
develop and implement a formal Watershed Management Plan.
The SNRE plans to follow this student project with another,
presumably Phase 2.
The plan focuses on three areas: water quality, conservation of
natural areas, and laws and ordinances. The water quality
section contained an assessment based on eight sampling
138
locations along three tributaries in the watershed: Hazen Creek,
Evans Creek, and River Raisin. Each sampling location was
tested three times, once in August and November of 2005, then
again in March of 2006. Analysis was conducted on the
samples for Total Phosphorus (TP), Soluble Reactive
Phosphorus (SRP), Ammonia, Nitrate, and Total Suspended
Matter. TP results ranged from approximately 20 - 175 µg/L,
while SRP range from 1 - 35 µg/L. Nitrate results ranged from
approximately 0.2 – 5 mg/L.
The plan recommends expanding the riparian buffers as a
primary method for addressing elevated nutrient levels, noting
that more than 60% of the stream corridors sampled have
buffers of less than 16 meters. It further recommends
integrating the analysis and recommendations of the Phase 1
study into a comprehensive Rive Raisin Watershed
Management Plan.
NOTE:
“The River Raisin Watershed Management Plan - Phase 1”
is a University of Michigan student research project that is
intended to inform the development of a State approved
watershed management plan. It is NOT a watershed
management plan. The River Raisin Watershed Council is
currently working to develop a formal watershed
management plan for the Raisin.