KETCHUM LAKE -- SNOHOMISH COUNTY: 1995

Lake Ketchum is located three miles north of Stanwood. It is fed by two unnamed intermittent inlets, and drains via an unnamed intermittent outlet to Skagit Bay.

Size (acres)                          24
Maximum Depth (feet)                  21
Mean Depth (feet)                     12
Lake Volume (acre-feet)              288
Drainage Area (square miles)        0.52
Altitude (feet)                      190
Shoreline Length (miles)             1.3

Contour Map

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


VOLUNTEER-COLLECTED SECCHI DATA
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Date      Temperature      Water      %Cloud Recent        Secchi Lake  
(Y/M/D)    (C)   (F)  pH   Color      Cover  Rain   Wind   (ft)   Ht(in) Abbrev. Comments
________________________________________________________________________________________________________________________

There are no Secchi data available for 1995.

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LABORATORY RESULTS
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                    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)
________________________________________________________________________________________________________________________
        STATION 1
95/05/21       E     347        1.40       13.3                                                                  
95/05/21       H    1092        1.11                                                                             
95/09/05       E     448        1.87        111                                                                  
95/09/05       H     492        1.26                                                                             
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E=epilimnion composite, H=hypolimnion composite.  Remarks codes: U = Below detection limits; J = Estimate.


SUMMARY OF VOLUNTEER SURVEY


There was no survey response for 1995.

FIELD OBSERVATIONS OF ECOLOGY STAFF
Heavy blue-green algal blooms were observed during the field visits, most likely
Aphanizomenon.  Substantial duckweed (Lemma sp.) observed along the shoreline.
Approximately 50 Daphnia collected in the 500ml filtrate during the summer sampling.


TROPHIC STATUS
Estimated Trophic State:                                 Eutrophic
Mean Trophic State Index (Secchi):                       55N* (Eutrophic)
Mean Trophic State Index (Total Phosphorus):             92 (Eutrophic)
Mean Trophic State Index (Chlorophyll a):                71 (Eutrophic)

*The calculated TSI is an estimate.  The Secchi disk hit bottom (B), entered the weeds
(W), or there were too few valid readings (N), or the calculation was based on
qualified data (J), or TSIP was based on spring data (S).

SUMMARY AND EXPLANATION OF TROPHIC STATE ASSESSMENT
This lake is hyper-eutrophic based on the elevated phosphorus and chlorophyll TSI
values.  Also, there was a near anoxic hypolimnion and a strong H2S odor detected in
the hypolimnion water samples. 


COMMENTS FROM 92/08/31 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.)Lemna
minor (duckweed)  Lemna sp. (duckweed)  Nuphar lutea (yellow
water-lily)  Typha sp. (cat-tail)

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

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