Formosa (Orange County)

Florida LAKEWATCH Water Chemistry Summary

Location: Latitude 28°34'7", Longitude 81°22'9"

Period of record: 80 sampling dates; March 10, 1991 to December 7, 1999

Surface area (Shafer et al. 1986): 29 acres / 12 hectacres

Lake Region (Griffith et al. 1997): Orlando Ridge

Geologic formation (Brooks 1981):

The geology is dominated by phosphatic sand, silty sand, and clay of the Hawthorne Formation.

Physiographic region (Brooks 1981):

The water body lies in the Orlando Promontory division of the Central Lake District.

Long-term Florida LAKEWATCH Data

Numbers reported below are the minimum, average, and maximum value for the 80 months sampled:

 

Minimum

Average

Maximum

Long-term total phosphorus concentrations (µg/L)

21

36

58

Long-term total nitrogen concentrations (µg/L)

370

770

1850

Long-term total chlorophyll concentrations (µg/L)

8.7

32.3

89.0

Long-term Secchi depth (ft)

1.0

3.3

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

Jan-19-99

30

520

16.3

6.0

Feb-09-99

21

370

11.3

5.5

Apr-06-99

32

570

9.3

5.8

May-04-99

38

730

14.0

2.7

May-28-99

46

1200

37.3

.

Aug-31-99

37

790

39.7

3.0

Sep-23-99

37

870

50.7

2.8

Oct-05-99

28

700

42.0

3.0

Nov-09-99

39

850

48.0

2.3

Dec-07-99

40

790

42.3

3.0

 

 

 

 

 

1999 Average

35

740

31.1

3.8

Formosa (Orange County)

Florida LAKEWATCH Aquatic Plant Summary

Aquatic plant data collected on June 17, 1992

Percent area covered with aquatic vegetation (PAC, %)

2

Percent of lake's volume filled with vegetation (PVI, %)

0

Average emergent plant biomass (kg wet wt/m2)

2.5

Average floating-leaved plant biomass (kg wet wt/m2)

0.4

Average submersed plant biomass (kg wet wt/m2)

7.4

Average width of emergent and floating-leaved zone (ft.)

12

Average lake depth (m)

4

Frequency that plant species occur in 10 evenly spaced transects around the lake.

Common Name

Plant Species

Frequency (%)

tapegrass

Vallisneria americana

90

torpedograss

Panicum repens

80

water-pennywort

Hydrocotyle umbellata

70

hydrilla

Hydrilla verticillata

50

flat-sedge

Cyperus odoratus

50

alligator-weed

Alternanthera philoxeroides

30

pickerelweed

Pontederia cordata

30

giant bulrush

Scirpus californicus

20

duck-potato

Sagittaria lancifolia

10

spatterdock

Nuphar luteum

10

fragrant water-lily

Nymphaea odorata

10

variableleaf pondweed

Potamogeton diversifolius

10

elephant-ear

Colocasia esculenta

10

soft rush

Juncus effusus

10

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