Keene (Hillsborough County)
Florida LAKEWATCH Water Chemistry Summary
Location: Latitude 28°8'40", Longitude 82°26'45"
Period of record: 47 sampling dates; July 14, 1991 to November 6, 1999
Surface area (Shafer et al. 1986): 31 acres / 13 hectacres
Lake Region (Griffith et al. 1997): Land-O-Lakes
Geologic formation (Brooks 1981):
The geology is dominated by argillaceous to sandy impure limestone of the Tampa Formation.
Physiographic region (Brooks 1981):
The water body lies in the Land-O-Lakes subdivision of the Tampa Plain division of the Ocala Uplift District.
Supplemental, unpublished water chemistry data, University of Florida.
Numbers reported below are the average for 1 month sampled:
|
pH |
7.1 |
Sulfate (mg/L) |
12.0 |
|
Total alkalinity (mg/L as CaCO3) |
21.0 |
Calcium (mg/L) |
10.0 |
|
Conductance (µS/cm @ 25 °C) |
179 |
Magnesium (mg/L) |
3.0 |
|
Color (Pt-Co units) |
119 |
Sodium (mg/L) |
17.0 |
|
Chloride (mg/L) |
39.5 |
Potassium (mg/L) |
4.3 |
|
Silicon (mg/L) |
0.4 |
|
|
Long-term Florida LAKEWATCH Data
Numbers reported below are the minimum, average, and maximum value for the 47 months sampled:
|
|
Minimum |
Average |
Maximum |
|
Long-term total phosphorus concentrations (µg/L) |
23 |
39 |
75 |
|
Long-term total nitrogen concentrations (µg/L) |
850 |
1280 |
2090 |
|
Long-term total chlorophyll concentrations (µg/L) |
4.0 |
24.8 |
110.7 |
|
Long-term Secchi depth (ft) |
1.6 |
3.4 |
6.0 |
1999 Florida LAKEWATCH Data
Numbers reported below are monthly averages calculated from 3 stations for total phosphorus (TP, µg/L), total nitrogen (TN, µg/L), chlorophyll (CHL, µg/L) and Secchi depth (SECCHI, ft) during 1999:
|
Date |
TP (µg/L) |
TN (µg/L) |
CHL (µg/L) |
SECCHI (ft |
|
May-01-99 |
35 |
1340 |
23.7 |
2.5 |
|
Jun-29-99 |
34 |
940 |
19.7 |
2.5 |
|
Nov-06-99 |
32 |
980 |
15.3 |
2.8 |
|
|
|
|
|
|
|
1999 Average |
34 |
1080 |
19.6 |
2.6 |
Keene (Hillsborough County)
Florida LAKEWATCH Aquatic Plant Summary
Aquatic plant data collected on May 13, 1992
|
Percent area covered with aquatic vegetation (PAC, %) |
0 |
|
Percent of lake's volume filled with vegetation (PVI, %) |
0 |
|
Average emergent plant biomass (kg wet wt/m2) |
3.2 |
|
Average floating-leaved plant biomass (kg wet wt/m2) |
3.9 |
|
Average submersed plant biomass (kg wet wt/m2) |
0.1 |
|
Average width of emergent and floating-leaved zone (ft.) |
16 |
|
Average lake depth (m) |
2 |
Frequency that plant species occur in 10 evenly spaced transects around the lake.
|
Common Name |
Plant Species |
Frequency (%) |
|
floating water-hyacinth |
Eichhornia crassipes |
90 |
|
torpedograss |
Panicum repens |
90 |
|
water-pennywort |
Hydrocotyle umbellata |
70 |
|
common salvinia |
Salvinia rotundifolia |
60 |
|
alligator-weed |
Alternanthera philoxeroides |
50 |
|
slender spikerush |
Eleocharis baldwinii |
50 |
|
smartweed |
Polygonum hydropiperoides |
50 |
|
cat-tail |
Typha spp. |
50 |
|
para grass |
Brachiaria mutica |
50 |
|
green algae |
Chlorphyta |
50 |
|
southern naiad |
Najas guadalupensis |
40 |
|
baby-tears |
Micranthemum umbrosum |
20 |
|
hydrilla |
Hydrilla verticillata |
20 |
|
water primrose |
Ludwigia octovalvis |
20 |
|
maidencane |
Panicum hemitomon |
20 |
|
spatterdock |
Nuphar luteum |
10 |
|
pickerelweed |
Pontederia cordata |
10 |
|
willow |
Salix spp. |
10 |