|
Ostras
River Hydrographic Region
The
Ostras River (click here
to see the map) drains an area of over 157
square kilometres. The watershed includes
towns and villages such as Rio das Ostras,
Cantagalo, Iriri, Âncora and Palmeiras. About
27,000 people live in the watershed including
a large part of the City of Rio das Ostras.
There are 2 municipalities within the valley.
An estimated 5% of the watershed is forested.
Additional
pertinent data is listed below:
Watershed
|
Area
|
157
sq.km
|
|
Terrestrial
Perimeter
|
75
km
|
|
Greatest
distance east to west
|
21
km
|
|
Greatest
distance north to south
|
16
km
|
|
Elevation
extreme:
|
610m
|
|
Highest
waterfall:
|
Unknow
|
|
Municipalities:
|
Rio
das Ostras and Casemiro de Abreu
|
|
Water
Use
|
withdrawal
uses (agricultural, mining) and instream
use (water transport, freshwater fisheries,
wildlife, recreation, wastewater
disposal).
|
|
Rainfall
|
1,500mm
|
River
|
Birth
place:
|
Careta,
Pote and Seca Hills
|
|
Source
streams:
|
Jundiá
and Iriri rivers
|
|
Length
from source to mouth
|
6.4
km
|
|
Location
of the mouth:
|
Atlantic
Ocean (Rio das Ostras City)
|
|
Major
Tributaries:
|
Maurício
river
|
|
Average
discharge of mouth (m3/s):
|
Unknow
|
|
Sediment
Discharge (103t/yr)
|
Unknow
|
|
Biodiversity
|
46
species of fish
|
|
Primary
threat
|
Channelization,
urban sprawl, agriculture and raw
sewage.
|
Lagoons
| |
Iriri
Lagoon
|
Salgada
Lagoon
|
Itapebussus
Lagoon
|
|
Area
(ha)
|
12
|
14
|
10
|
|
Shoreline
(km)
|
2.65
|
2.79
|
2.66
|
|
Lenght
(km)
|
0.63
|
0.38
|
0.78
|
|
Width
(km)
|
0.71
|
0.82
|
0.51
|
Source:
CILSJ
São
João River Hydrographic Region
The
São João River watershed (click here
to see the map) extends
through 8 municipalities
over a surface of 2,160 sq. km. The river runs east for about
55 km then flows into Juturnaiba Reservoir.
Approximately 65 km downstream from the dam,
it discharges into the Atlantic Ocean. The
main river is some 120 km long and it is fed
by several tributaries. The São João river
pulsates once a year. From November through
March the volume of the mainstream swells.
During the second half of the year, the flow
diminishes. About 90,000 people live in the
watershed, in cities such as Rio Bonito, Silva
Jardim, Casemiro de Abreu and Rio das Ostras,
as well as in several villages. The river
is navigable for small vessels. An estimated
30% of the watershed is forested. The rivers
and their floodplains are used for many purposes
and are among those habitats most severely
affected by human activity. Channelisation
of rivers and drainage of wetlands and riparian
areas are the main problems.
Additional
pertinent data is listed below:
Watershed
|
Area
|
2.160
sq.km
|
|
Perimeter
|
266
km
|
|
Greatest
distance east to west
|
67
km
|
|
Greatest
distance north to south
|
43
km
|
|
Elevation
extreme:
|
1.719m
|
|
Highest
waterfall:
|
Unknow
|
|
Municipalities:
|
Cachoeiras
de Macacu, Rio Bonito, Casimiro de Abreu,
Araruama, São Pedro da Aldeia, Cabo
Frio, Rio das Ostras e Silva Jardim.
|
|
Water
Use
|
Withdrawal
uses (municipal, industrial, agricultural,
mining) and instream use (water transport,
freshwater fisheries, wildlife, recreation,
wastewater disposal).
|
|
Rainfall
|
1,500mm
- 2,500mm
|
River
|
Birth
place:
|
Sambê
Mountain (800m)
|
|
Length
from source to mouth:
|
120
km
|
|
Location
of the mouth:
|
Atlantic
Ocean near Barra de São João Village
|
|
Major
Tributaries:
|
Capivari,
Bacaxá, Gaviões, do Ouro, Gargoá, Panelas,
São Lourenço, Águas Claras, dos Pirineus
ou Crubixais, Riachão, Bananeira, Maratuã,
Aldeia Velha, Indaiaçu, Lontra and Dourado
rivers.
|
|
Dam
|
Juturnaíba
|
|
Average
discharge of mouth (m3/s):
|
Unknow
|
|
Sediment
Discharge (103t/yr)
|
Unknow
|
|
Biodiversity
|
89
species of fish
|
|
Primary
threat
|
Dam,
channelization, urban sprawl, agriculture,
mining, resource extraction, water diversions,
raw sewage, invasive species, etc.
|
Juturnaíba
Reservoir
Juturnaíba
reservoir (click here
to see the map) is the
principal water supply source for almost the
whole region. The
reservoir and its dam are owned by the Federal
Government and operated by Prolagos under
an agreement with the Rio de Janeiro State
Government.
Juturnaiba
dam was constructed in 1982 to control flooding
and to supply water for drinking, industry
and agricultural use. Located
on the São João river, the reservoir has a
maximum depth of 8m and an area of 43 km².
The São João, Bacaxá, Capivari and Onças rivers
are the major sources
of water flowing into reservoir. The
drainage area that contributes to reservoir
is 1,370 square km. The water
produced by Juturnaíba requires some treatment
by a water treatment plant to make it safe
for drinking.
More
detail:
Dam
|
Type
|
Earth
and rock dam.
|
|
Length
|
710m
|
|
Crest
Elevation
|
11m
|
|
Date
of Closure
|
1982
|
|
Impoundment
Began
|
1982
|
|
Construction
Period:
|
1978-1984
|
Reservoir
|
Catchment
area
|
1,370
sq. km.
|
|
Volume
|
10
million cubic meters
|
|
Reservoir
elevation
|
8.4
m above sea level
|
|
Surface
Area
|
43
sq. km
|
|
Shoreline
|
85
km
|
|
Length
|
15
km
|
|
Width
(maximum)
|
4
km
|
|
Maximum
depth
|
8m
|
|
Mean
depth
|
2.3m
|
|
Annual
Inflow
|
29
m3/s
|
|
Retention
time
|
38
days
|
Una
River and Cape Búzios Hydrographic Region
Una
River and Cape Búzios Hydrographic Region (click here
to see the map) covers 626 sq.km. It includes
Armação dos Búzios, Cabo Frio, São Pedro da
Aldeia, Iguaba Grande and Araruama municipalities;
the Armação dos Buzios City and some villages
such as Tamoios, São Vicente and Rasa.
The
region is formed by the Una River basin and
small watersheds located in the Cape Buzios
and Peró coastalplain.
Additional
pertinent data is listed below:
Una
River Watershed
|
Area
|
480
sq. km
|
|
Greatest
distance east to west
|
30
km
|
|
Greatest
distance north to south
|
24
km
|
|
Elevation
extreme:
|
Sapiatiba
Mountain
|
|
Municipalities:
|
Armação
dos Búzios, Cabo Frio, São Pedro da
Aldeia, Iguaba Grande and Araruama.
|
|
Water
Use
|
Withdrawal
uses (agricultural, municipal)
and instream use (freshwater fisheries,
wildlife, recreation, wastewater disposal).
|
|
Rainfall
|
800mm
- 1,500mm
|
Una
River
|
Birth
place:
|
Igarapiapunha
Hill
|
|
Source
streams:
|
Godinho
stream
|
|
Length
from source to mouth
|
23
km
|
|
Location
of the mouth:
|
Unamar
beach, Atlantic Ocean
|
|
Major
Tributaries:
|
Conceição,
Carijó, Papicu and Frecheiras rivers
|
|
Average
discharge of mouth (m3/s):
|
Unknow
|
|
Sediment
Discharge (103t/yr)
|
Unknow
|
|
Primary
threat
|
Channelization,
agriculture and raw sewage.
|
Lagoons
Geribá,
Ferradura, do Canto, dos Ossos or da Usina
and Brejo da Helena.
Araruama
Lagoon and Cape Frio Hydrographic Region
Araruama
Lagoon and Cape Frio Hydrographic Region (click
here to see
the map) covers 572 sq. km and 7 municipalities:
Saquarema, Araruama, Iguaba Grande, São Pedro
da Aldeia, Cabo Frio, Arraial do Cabo and
Rio Bonito. It is formed
by the Araruama watershed, the Massambaba
and Cabo Frio sandbars and the Cape Frio.
It is a home of 260,000 full-time inhabitantes.
The
hydrographic region encompasses several streams
and lagoons, such as Araruama, one of
the largest hypersaline lagoon in the world,
as well as Jaconé Pequena, Vermelha, Pitanguinha,
Pernambuca and Azul lagoons. Das Moças and
Maratuna, the largest streams flowing into
Araruama lagoon, are found on the west side
of the basin. To the east, a number of smaller,
mainly ephemeral creeks, drain towards the
lagoon.
Araruama
is a natural paradise. This
magnificent lagoon, whose aboriginal name
can be translated roughly as “the place where
there are lot of shells”, is one of the most
important tourist resorts of the Rio de Janeiro
State. Araruama
lies parallel to the coast and is connected
to the sea by a long and narrow channel, called
Itajuru, that strongly dampens water exchange.
Aspects of the extern
and intern morphology suggests that the evolution
of the lagoon is related to sea transgressions
and regressions during the Quaternary.
Araruama
has an area of 220 sq. km. It
is 37 kilometers long, with a maximum width
of 13 kilometers. Although
the lagoon is largely shallow between 0.5
- 1.5 m, it has holes up to 17 m depth. Araruama
is one of the few
hypersaline lagoon systems in the world, a
body of water even saltier than most seawater,
because the climate is semiarid and
there is a negligible river runoff relative
to the large volume. Salinity varies from
35 to 43 psu in the narrow channel that connects
with the sea and from 56 to 77 psu in the
inner lagoon. Carbonate-rich sediments are
covered with 1-3 mm thick microalgal mats,
dominated by the cyanobacteria Phormidium
sp., Oscillatoria sp., and Lyngbya
sp. in shallow areas.
Araruama
is composed of seven semi-open embayments,
delimited by sand spits, one coastal
landform resulting from both the constructive
and destructive forces of the lagoon. Spits
are elongate ridges of sand that project from
land and end in open water. The development
of spits is mainly related to the circulation
pattern and the distribution of barrier material.
Araruama has 5 spits
that formed along the lagoon's southern shore.
The
land around Araruama lagoon was one of Brazil’s
most important salt-producing regions, and
the windmills, that pull the saline solution
up to the surface, dominate the skyline. The
saltpans into which the solution emerges are
of various sizes but are always square and
arranged juxtaposed like a great patchwork
quilt, speckled with small piles of salt brushed
into heaps from the surface of the pans. Artisanal
fisheries and salt extraction were the principal
economic activities till the 50´s. Since then,
increase of land prices caused by enhanced
tourism and domestic sewage inputs promoted
conflicts between economic uses.
Additional
pertinent data is listed below:
Araruama
Lagoon and Itajuru Channel
|
Lagoon
Morphology
|
|
Age
|
5,000
- 7,000 years old
|
|
Surface
Area
|
220
sq. km
|
|
Elevation
|
Sea
level
|
|
Shoreline
|
160
km
|
|
Length
(maximum)
|
37
km
|
|
Width
(maximum)
|
13
km
|
|
Maximum
depth
|
17
m
|
|
Mean
depth
|
0.5
- 1.5 m
|
|
Northernmost
point
|
São
Pedro Beach
|
|
Southernmost
point
|
Monte
Alto Beach
|
|
Easternmost
point
|
Anjo
Island
|
|
Westernmost
point
|
Barreiro
Beach
|
|
Northernmost
community
|
São
Pedro City
|
|
Southernmost
community
|
Praia
Seca and Monte Alto Villages
|
|
Easternmost
community
|
Cabo
Frio City
|
|
Westernmost
community
|
Araruama
City
|
|
Inlets
|
12
- Ponte dos Leites, Convento, Parati,
Iguabinha, Iguaba, São Pedro da Aldeia,
Tiririca (Ingá ou Açaí), Rebolo (Acaíra
ou Coroinhas),Figueira (Gaivotas ou
do Atalho), Tucuns (Massambaba ou Martins),
Maracanã and Palmeiras
|
|
Points,
Spits and Headlands
|
28
|
|
Beachs
|
54
|
|
Islands
|
10
|
|
Coastal
ecosystems
|
Sand
beaches with rockshores and mangroves
in same spots
|
|
Coastal
Cities and Villages
|
Araruama,
Iguaba Grande, São Pedro da Aldeia,
Arraial do Cabo and Cabo Frio cities
and Iguabinha, Praia Seca, Monte Alto
and Figueira Villages.
|
|
Historic
Sites
|
Mossoró
and Palmer channels; Feliciano Sodré
Bridge; Perynas
Saltpan
(first
saltpan in Brazil – 1823).
|
|
Itajuru
Canal Morphology
|
|
Length
|
5.5
km
|
|
Width
|
100
– 300 m
|
|
Maximum
depth
|
5
m (mouth)
|
|
Mean
depth
|
0.5-
2.0 m
|
|
Salinity
|
35.5
–46.87 ‰
|
|
Bridges
|
3
|
|
Water
and Botton
|
|
Volume
(km3)
|
0.618
|
|
River
Flow to the Lagoon
(average discharge):
|
2.3
m3/s
|
|
Calculated
flushing half-time
|
84
days
|
|
Salinity
|
52
‰
|
|
Mean
Lagoon tidal range
|
1
cm
|
|
Average
Temperature
|
26ºC
|
|
Water
colour
|
Blue
and Green
|
|
Primary
Producers
|
Algal
mat
|
|
Trophic
State Classification
|
Oligo-Mesotrophic
|
|
Biodiversity
|
98
species of algae, 39 of fish and more
than 100 of benthic invertebrates
|
|
Mangrove
|
3
|
|
Uses
|
Wildlife
and fish habitat, swimming, volleyball
beach, fishing, crab gathering in mangroves, marinas, sailing,
kayak, transport, salt production and
mud
that is said to be effective in treating
rheumatic and dermatological conditions;
|
Source:
CILSJ and UFF
Araruama
Watershed
|
Population:
|
Nearly
260,000 full-time residents and more
than 500,000 during summer season.
|
|
Area:
|
404
sq.km
|
|
Elevation
extreme:
|
Castelhana
Peak (594m)
|
|
Saltpan
surface
|
60
sq. Km
|
|
Municipalities:
|
Saquarema,
Araruama, Iguaba Grande, São Pedro da
Aldeia, Cabo Frio and Rio Bonito
|
|
Water
Use
|
Withdrawal
uses (agricultural, mining) and instream
use (wildlife, recreation, wastewater
disposal).
|
|
Rainfall
|
750mm
– 900 mm
|
|
Major
Rivers
|
Moças
and Mataruna rivers
|
|
Average
discharge (m3/s):
|
2,3
|
|
Sediment
Discharge (103t/yr)
|
Unknow
|
|
Aquatic
Biodiversity
|
Unknow
|
|
Primary
threat
|
Channelization,
urban sprawl, mining, water diversions,
raw sewage.
|
Source:
CILSJ
Other
Lagoons
|
Lagoon
|
Year
|
Area
(sq.
km)
|
Shoreline
(km)
|
Length
(km)
|
Width
(m)
|
Water
|
|
Jaconé
Pequena
|
1956
|
0,59
|
3,33
|
1
|
800
|
Freshwater
and brackish
|
|
Vermelha
|
1962
|
2,5
|
10,88
|
4,3
|
750
|
Salted
|
|
Pitanguinha
|
1956
|
0,55
|
3,5
|
1,5
|
750
|
Salted
|
|
Pernambuca
|
1956
|
1,89
|
12,34
|
5
|
550
|
Salted
|
|
Azul
|
1966
|
0,28
|
2,12
|
0,8
|
600
|
Unknow
|
Source:
CILSJ
Saquarema,
Jacone and Jacarepiá Lagoons Hydrographic
Region
This
Hydrographic Region (click here
to see the map) covers 310 sq.km, and encompasses
two municipalities (Saquarema and Maricá),
several streams
and 6 lagoons, such as Saquarema, Jaconé,
Jacarepiá, Nova, Marrecas and Ipitangas. It
is composed of three watersheds, as showed
in the table below.
|
Feature
|
Watershed
|
|
Saquarema
Lagoon
|
Jaconé
Lagoon
|
Jacarepiá
Lagonn
|
|
Area
|
215
|
30
|
65
|
|
Major
Rivers
|
Rios
Roncador ou Mato Grosso, Tingui, Mole,
Jundiá, Seco, Padre e Bacaxá.
|
Rio
Grande de Jaconé
|
Rio
Fazendinha
|
|
Population:
|
Nearly
52,000 full-time residents.
|
|
Rainfall
|
1,000-1,300mm
|
|
Greatest
distance east to west
|
26
km
|
|
Greatest
distance north to south
|
14
km
|
|
Elevation
extreme:
|
Lajinha
peck, 879m
|
|
Highest
waterfall:
|
Tingui
fall
|
|
Water
Use
|
Withdrawal
uses (agricultural, mining) and instream
use (wildlife, recreation, wastewater
disposal).
|
|
Average
discharge (m3/s):
|
Unknow
|
|
Sediment
Discharge (103t/yr)
|
Unknow
|
|
Aquatic
Biodiversity
|
Unknow
|
|
Primary
threat
|
Channelization,
urban sprawl, mining, water diversions,
raw sewage.
|
Source:
CILSJ
Saquarema
is an ecosystem formed by four lagoon cells:
Mombaça (or Urussanga), Jardim, Boqueirão
ande Fora (or Saquarema). Jaconé
lagoon is connected to Urussanga by a long
and narrow canal.
|
Feature
|
Saquarema
Lagoon Cells
|
|
Urussanga
|
Jardim
|
Boqueirão
|
de
Fora
|
|
Area
(km²).
|
13,7
|
3,4
|
0,9
|
6,0
|
|
Length
(maximum)
(km)
|
4,4
|
2,5
|
1
|
4,0
|
|
Width
(maximum) (km)
|
4,5
|
1,9
|
0,8
|
2,8
|
Source:
CILSJ
Additional
pertinent data is listed below:
| |
SAQUAREMA
LAGOON
|
JACONÉ
LAGOON
|
JACAREPIÁ
LAGOON
|
|
MORPHOLOGY
|
|
Surface
Area (sq km)
|
24
|
4.0
|
1.5
|
|
Shoreline
(km)
|
45
|
8,0
|
7.5
|
|
Elevation
(m)
|
Unknow
|
Unknow
|
Unknow
|
|
Length
(maximum)
(km)
|
11.9
|
2.8
|
1.5
|
|
Width
(maximum) (km)
|
4.5
|
1.3
|
1.3
|
|
Maximum
depth (m)
|
2.9
|
1.5
|
-
-
|
|
Mean
depth (m)
|
1,2
|
0.8
|
0.4
|
|
Beachs
|
1
|
--
|
--
|
|
Islands
|
2
|
0
|
1
|
|
Coastal
ecosystems
|
Wetland,
mangrove, rocky shore and beach
|
wetland
|
wetland
|
|
Coastal
Cities and Villages
|
Saquarema
City
|
Jaconé
Village
|
-
-
|
|
WATER
AND BOTTON
|
|
Volume
(km3)
|
0.025
|
0.004
|
Unknow
|
|
River
Flow to the Lagoon
(average discharge):
|
Unknow
|
Unknow
|
Unknow
|
|
Calculated
flushing half-time (days)
|
22
(Urussanga) 7 (de Fora)
|
25
|
Unknow
|
|
Salinity
(‰)
|
20
(Urussanga) 1 (de Fora)
|
5
|
Unknow
|
|
Mean
Lagoon tidal range (cm)
|
2
(Urussanga) 4 (de Fora)
|
1
|
|
|
Average
Temperature (ºC)
|
25
|
Unknow
|
Unknow
|
|
Primary
Producers
|
Phytoplancton
|
Unknow
|
Unknow
|
|
Trophic
State Classification
|
Eutrophic
|
Unknow
|
Unknow
|
|
Biodiversity
|
30
species of fish
|
Unknow
|
Unknow
|
|
Mangrove
|
Yes
|
No
|
No
|
|
Uses
|
Wildlife
and fish habitat, swimming, fishing,
crab gathering in mangroves and kayak
|
Source:
CILSJ and UFF
|
