This document discusses water quality in Sarasota Bay and provides examples of low impact development (LID) principles in action. It notes that stormwater runoff is a major pollution concern impacting Sarasota Bay. Before urbanization, natural areas filtered stormwater into the ground, but after urbanization, impervious surfaces increase runoff. North Water Tower Park in Sarasota underwent restoration to address this by implementing LID techniques like rain gardens to filter and infiltrate stormwater on site. The document provides examples of various LID principles like rain barrels, cisterns, permeable pavers, green roofs, and explains how they improve water quality by reducing and treating stormwater runoff.

1. Water Quality in Sarasota Bay
LID in Action

2. Pretest
1. What is a watershed?
a. The land over which water flows into a body of water
b. The body of water that it flows into
2. What is an estuary? a. Where fresh & salt-water meet
b. A saltwater lagoon
3. Agricultural runoff is an example of
a. point source b. non-point source pollution
4. Which is an example of a Low Impact Development
Principle? a. Aquifer storage & recovery b. Rain garden
5. Which would hold more oxygen? a. cold water
b. warm water
6. Increased urbanization affects the estuary by:
a. less pollution b. more runoff

3. What can happen to a raindrop as it
falls?
•Seep or percolate
into the soil
•Evaporate back to
the atmosphere
•Runoff the land
into a body of
water
Water always runs downhill

4. What is a watershed?
An area of land
over which
water flows
into a body of
water
(ponds, rivers,
streams lakes
etc)
We all live in a watershed

5. Where are you now?

6. Sarasota Bay Watershed

7. North Water Tower Park
A 20-acre natural oasis in the midst of the City of Sarasota’s urban landscape

8. North Water Tower Park
• Network of ditches carrying polluted water
away from the park
• Water flows to Whitaker Bayou and then
Sarasota Bay
• Stormwater is the major pollution concern
impacting Sarasota Bay
• Before urbanization, natural areas filtered
stormwater into the ground.
• After urbanization, impervious surfaces
create runoff

9. North Water Tower Park
Restoration Partners
• Sarasota Bay Estuary Program
• EPA Gulf of Mexico Program Grant
• Around the Bend Nature Tours
environmental education
• Sarasota County
• SWFWMD Grant – design & construction
• City of Sarasota
• Urban Design Studio – form-based code

10. North Water Tower Park
Education Component
• LID – Low Impact Development
• Water Quality testing
• Service Learning – exotic plant removal
• Air potato is a member of the yam family
Dioscoreaceae, which produces large
numbers of aerial tubers, potato-like
growths attached to the stems. These air
potatoes drop to the ground and grow into
new plants. Each vine is covered with
heart-shaped leaves and can quickly grow
60-70 feet in length.

11. Issues with Sarasota Bay Watershed
• Stormwater Runoff
• Loss of Habitat
• Loss of Wetlands

12. How have we altered the watershed?

13. So what can happen to this?
Anything we do to the land
within a watershed may have
an effect on the water within
that watershed.

14. So what can happen to this?
Anything we do to the land within a watershed may
have an effect on the water within that watershed.
Can this happen in Sarasota Bay?

15. What is pollution?
• Point source pollution
• Nonpoint source pollution
Contamination of water by
harmful materials

16. Point source pollution
• Comes from a specific location and can easily
identified
You can point your
finger at the location

17. Nonpoint Source Pollution
• Pollution that comes from a variety of
different sources which make it difficult to
identify.
• Enters the waterways by being washed off
lawns and roadways during a storm.
Stormwater runoff

18. Comparison of point and nonpoint
source pollution

19. Stormwater ponds
• Stormwater ponds
collect stormwater and
release it slowly which
helps prevent flooding.
• Has limitations for
water quality.

20. Improve Stormwater ponds
Plant vegetation
– Buffer wave action
– Absorb nutrients
– Prevent erosion
– Attract wildlife

21. What is LID?
Low Impact Development
Stormwater management systems
an innovative stormwater management approach with a basic principle
that is modeled after nature

22. – Water is engineered to channel away from
buildings and walkways
– Less water goes into the ground, thus lowering
water tables
– Surface water is often contaminated runoff
– Wetlands are drained for
residential and
commercial development
Current Development Practices
result in Impaired Hydrology

23. The diagrams show how groundwater infiltration decreases and
surface runoff increases dramatically as a watershed is developed.

24. The diagrams show how groundwater infiltration decreases and
surface runoff increases dramatically as a watershed is developed.

25. The diagrams show how groundwater infiltration decreases and
surface runoff increases dramatically as a watershed is developed.

26. The diagrams show how groundwater infiltration decreases and
surface runoff increases dramatically as a watershed is developed.

27. The diagrams show how groundwater infiltration decreases and
surface runoff increases dramatically as a watershed is developed.

28. Low Impact Development Techniques
Rain Barrels & Cisterns
Rain Gardens
Tree Box Filters
Soil Amendments
Permeable Pavers
Green Roofs

29. Rain Barrels
Recycle the Rain!

30. Cisterns
A cistern is more expensive than a rain barrel, but it is a
more comprehensive system to provide water
for the entire landscape.

31. Rain Gardens
Plant a rain garden!
Rain gardens are designed to reduce stormwater
that runs off individual properties into our bays.

32. Rain Gardens
10,000 Rain Gardens Project

33. Soil Amendments
Soil amendments improve the physical
properties of soils.
The best soil amendments increase
water- and nutrient-holding capacity and
improve aeration and water infiltration.

34. Tree Box Filters
Infiltration Filters

35. Runoff is directed to the tree box filter, where it is cleaned by
vegetation and soil before entering a catch basin. The runoff
collected in the tree-boxes helps irrigate the trees.
TREE BOX

36. Permeable Pavers

37. Pervious Concrete
Asphalt – standard 
Concrete – pervious 
• Created with large air spaces
• Allows water to soak right in
• Less polluted runoff to Sarasota Bay
• More infiltration to groundwater

38. Reduce Pavement and Increase
“Green Space”

39. Green Roof

40. Green Roof Components

42. What are
your ideas?
Think about where you live
• What watershed do you live in?
• What can you do to protect your watershed?
• Could you use any of the low impact
development techniques presented here?

43. Fred the Fish
How does pollution affect our wildlife?
• What happens to Fred the Fish as he travels
down a river?

44. Fred meanders down the river.
How is Fred???

45. Fred swims into farm country. He
passes by a plowed riverbank.
How is Fred???
Turbidity –
measure of
how clear the
water is

46. Fred nears a housing development.
Fertilizers are used by farms and lawns
are washed into the water
How is Fred????
Plants grow
Causes an algae bloom
Plants die
Decomposers break down the
decaying plants
Bacteria use up oxygen
Dissolved oxygen in water
decreases
Dissolved oxygen, Phosphate and
Nitrate

47. Fred now swims under a bridge.
How is Fred???

48. Fred continues his journey and passes
a group of cows.
How is Fred??
Dissolved Oxygen,
Nitrate
Animal
waste
Dissolved
oxygen

49. Fred swims past a park.
TRASH!!!!!!
How is Fred???

50. Fred swims past a factory. Hot water is
dumped into the river.
Hot water
holds less
oxygen
then cold
water.
How is
Fred????
Dissolved
oxygen and
temperature

51. Fred swims past a sewage treatment
plant.
How is Fred???
Dissolved oxygen
Human waste
DO, Nitrate and
Coliform

52. Poor Fred swims past a hazardous
waste dump.
Toxic
chemicals
are leaked
into the
river.
How is Fred??
pH is acidic or basic
or alkaline

53. How is Fred????

54. Water Quality Test
• Dissolved oxygen
• Temperature
• Turbidity
• Phosphate
• Nitrate
• pH
• Salinity

55. Temperature
• Temperature is important because it affects
the amount of dissolved oxygen in the water.
• Cold water will hold more oxygen than
warmer water.
• Thermal pollution from the factories can
cause temperature changes that can be
damaging to the aquatic ecosystem.

56. Dissolved Oxygen (DO)
Oxygen gas that is
dissolved in water
•DO is the most important to the
health of the water. All aquatic
animals need oxygen to survive.
•High levels of bacteria from
sewage or a large amount of
rotting plants can cause the % of
oxygen in the water to decrease.

57. pH
• pH -measurement of how acidic or basic the
water is.

58. Phosphate and Nitrate
• Plant nutrients
1. Plants grow and grow and grow
2. Causes an algae bloom
3. Plants die
4. Decomposers break down the decaying
plants
5. Bacteria use up oxygen
6. Dissolved oxygen in water decreases

59. Turbidity
• Turbidity: Measure of the water clarity
•
• Not the same as the color of the water. Dark
colored water can be still be clear.
• Caused by soil erosion, urban runoff and algal
blooms.

60. Salinity
• Amount of dissolved salt content in
water
–Sea water - 35 -50 ppt
–Brackish – 1 – 35 ppt
–Freshwater – under 1 ppt

61. Questions?