Lake St. Clair is located 6.5 miles northwest of Yelm. It is an irregularly shaped lake with steep sides, numerous narrow arms and four small islands. The lake is fed by Eaton Creek, drains to the Nisqually River, and seeps to McAllister Springs. The south arm of Lake St. Clair is a deep conical-shaped depression.

Size (acres)                         268
Maximum Depth (feet)                 110
Mean Depth (feet)                     32
Lake Volume (acre-feet)             8576
Drainage Area (square miles)        20.9
Altitude (feet)                       73
Shoreline Length (miles)            10.4

Contour Map

Source of morphometric data: Water Supply Bulletins 42, 43, and 57.

VOLUNTEER-COLLECTED SECCHI DATA ________________________________________________________________________________________________________________________ Date Temperature Water %Cloud Recent Secchi Lake (Y/M/D) (C) (F) pH Color Cover Rain Wind (ft) Ht(in) Abbrev. Comments ________________________________________________________________________________________________________________________ STATION 1 97/05/08 17.5 63.5 Undefined 0 None Calm 6.0 0.0 LAKE LEVEL RAISED DURING THE WINTER TO ABOUT THE LEVEL OF 3 OR 4 YEARS AGO (ABOUT NORMAL). VISABILITY POOR, A LOT OF FLOATING PARTICLES IN THE WATER (GREY GREEN COLOR). 97/05/18 21.0 69.8 Undefined 25 None Breezy 6.5 -3.0 A LOT OF ALGAE/PARTICLES FLOATING, NOT EVIDENT ON SURFACE. 97/06/10 21.0 69.8 Undefined 0 None Calm 8.5 3.0 WATER CLEARING UP. A LOT LESS FLOATING ALGAE. WATER VERY REDDISH COLORED. 97/06/23 20.0 68.0 Undefined 50 Light Light 7.5 0.0 LAKE HEIGHT STABLE NO CHANGE, DUE TO RAIN STILL A LOT OF ALGAE PARTICLE IN WATER, NONE ON SURFACE. WATER COLOR- REDDISH BROWN 97/07/07 22.0 71.6 Undefined 90 Light 7.0 -6.0 WATER WAS REDDISH-BROWN. 97/07/18 23.0 73.4 Undefined 10 Light 8.5 -2.0 WATER WAS REDDISH-BROWN 97/07/31 24.0 75.2 Undefined 10 None Light 8.5 -11.0 WATER WAS REDDISH-BROWN. 97/08/12 25.0 77.0 Undefined 1 None Light 8.0 0.0 COLOR - REDDISH BROWN, LILLY PADS TURNING BROWN OR BLACK EARLY - MAYBE THE HOT WEATHER 97/08/27 22.0 71.6 Undefined 75 Heavy Breezy 9.5 0.0 WATER WAS REDDISH-BROWN. 97/09/12 21.0 69.8 50 Trace Breezy 10.0 -1.5 LAKE IS UP COMPARED TO THIS TIME LAST YEAR. 97/09/22 20.0 68.0 Grn-brown 0 None Light 8.4 -2.0 INCREASE IN ALGAE. SOME FLOATING IN THE COVE. SEE A LOT ABOVE THE SECCHI. 97/10/11 15.0 59.0 Undefined 50 Mod Light 7.0 -2.0 WATER WAS REDDISH. ALGAE REDUCED CLARITY. HEAVY RAIN BROUGHT LAKE ABOVE NORMAL FOR THIS DATE 97/10/24 14.0 57.2 Grn-brown 25 Light 7.5 0.0 GREENISH ALGAE PARTICLES IN THE WATER. LAKE HEIGHT IS STABLE BUT HIGHER THAN LAST YEAR THIS TIME. ________________________________________________________________________________________________________________________
LABORATORY RESULTS ________________________________________________________________________________________________________________________ Total Total Fecal Col. Bacteria Turb- Suspended Solids Phosphorus Nitrogen Chlorophyll (colonies/100 mL) idity Total Non-Volatile Color Date Strata (ug/L) (mg/L) (ug/L) Site 1 Site 2 (NTU) (mg/L) (mg/L) (Pt-Co) ________________________________________________________________________________________________________________________ There are no LWQA Program chemistry data for this lake in 1997. ________________________________________________________________________________________________________________________
SUMMARY OF VOLUNTEER SURVEY WATER QUALITY----------------------------------------------------------------------- Overall water quality was good. The worst problems were reported as: 1. fluctuating water levels 2. algae 3. declining long-term trend Sources of actual or potential problems includes: PASTURE & FIELD DRAINAGE. INCREASE IN WILD GEESE. Were there days (and how many) when poor water quality impaired Fishing - NO(0) Swimming - NO(0) Aesthetics - NO(0) MANAGEMENT-------------------------------------------------------------------------- Did the lake receive chemical treatments this year? NO Were fish stocked this year? YES Any lake groups present (such as a lake association)? YES Any lake management activities this year? NO OTHER------------------------------------------------------------------------------- How many homes/new homes are there on the lake shore?~ 325-350 Changes since last year? A FEW NEW HOMES. NO HUGE DEVELOPMENT.
FIELD OBSERVATIONS OF ECOLOGY STAFF 8-20-97 Bryozoan mass spotted--larger mass at the Christopherson's dock.
TROPHIC STATUS Estimated Trophic State: Meso-eutrophic Mean Trophic State Index (Secchi): 47 (Mesotrophic) Mean Trophic State Index (Total Phosphorus): 0 (Not assessed) Mean Trophic State Index (Chlorophyll a): 0 (Not assessed)
SUMMARY AND EXPLANATION OF TROPHIC STATE ASSESSMENT TSI values and summertime hypolimnetic DO concentrations suggest a meso-eutrophic assessment. Dark water coloration inhibit substantial macrophyte and algal growth. It is suspected that most of the hypolimnetic oxygen demand is chemical in nature and not necessarily biological.
COMMENTS FROM 92/08/11 AQUATIC PLANT SURVEY Aquatic plants were surveyed at the public access and at one to three transects around the lake. A thorough survey was not made and the list below may be incomplete.
AQUATIC PLANT LIST (This list may be from multiple years and sources.) Brasenia schreberi (watershield) Ceratophyllum demersum (Coontail; hornwort) Elodea canadensis (common elodea) Iris pseudacorus (yellow flag) Najas sp. (water-nymph) Nitella sp. (stonewort) Nymphaea odorata (fragrant waterlily) Potamogeton amplifolius (large-leaf pondweed) Potamogeton robbinsii (fern leaf pondweed) Potamogeton zosteriformis (eel-grass pondweed) Scirpus sp. (bulrush) Typha latifolia (common cat-tail) Vallisneria americana (water celery)

Data collected and provided by Washington Department of Ecology's Lake Monitoring Program (Maggie Bell-McKinnon, phone 360- 407-6124).

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