Perkerra River: Difference between revisions

Coordinates: 0°32′05″N 36°05′33″E / 0.534632°N 36.092491°E / 0.534632; 36.092491
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| location =
| location =
| length =
| length =
| elevation =
| elevation = {{convert|2,400|m}}
| mouth_elevation = {{convert|1000|m}}
| mouth_elevation = {{convert|980|m}}
| discharge =
| discharge =
| watershed =
| watershed = {{convert|1207|km2}}<ref name=Onyando/>
| river_system =
| river_system =
| left_tribs =
| left_tribs =
| right_tribs =
| right_tribs =
}}
}}
The '''Perkerra River''' is a river in the [[Great Rift Valley, Kenya|Great Rift Valley]] in [[Kenya]] that feeds [[Lake Baringo]].
The '''Perkerra River''' is a river in the [[Great Rift Valley, Kenya|Great Rift Valley]] in [[Kenya]] that feeds the freshwater [[Lake Baringo]].
It is the only perennial river in the arid and semi-arid lands of the [[Baringo District]].<ref name=Natirrig/>
It is the only perennial river in the arid and semi-arid lands of the [[Baringo District]].<ref name=Natirrig/>
⚫
The Perkerra river supplies water to the Perkerra Irrigation Scheme in the Jemps flats near [[Marigat]] Township, just south of the lake.<ref name=chambers/>


==Catchment==
⚫
==Irrigation scheme==


The river has a catchment area of {{convert|1207|km2}}.<ref name=Onyando/>
⚫
The Perkerra river supplies water to the Perkerra Irrigation Scheme in the Jemps flats near [[Marigat]] Township, just south of the lake.
It rises on the western wall of the Rift valley at {{convert|8000|ft}}, dropping down to {{convert|3200|ft}} at its mouth on the lake.<ref name=chambers1973/>
This scheme was started in 1954 during the Emergency using detainees as labor and now supports about 670 farm households..
The catchment area has steep slopes on the hillsides, flattening out lower down.<ref name=Onyando/>
Most of the water comes from the hill slopes, where annual rainfall is from {{convert|1100|mm}} to {{convert|2700|mm}}.
The region around the lake is semi-arid, with annual rainfall of {{convert|450|mm}} and annual evaporation rates of {{convert|1650|mm}} to {{convert|2300|mm}}.<ref name=Akivaga/>

==Land use changes==

In the late 1800s the alluvial plains near the lake were occupied by the [[Njemps people]], an ethnic group related to the [[Maasai people|Maasai]].
They used a brushwood barrier to raise the level of the river and let the water flow over the flat ground. The barrier would be destroyed by the seasonal floods, needing to be replaced, but the system was stable.
With the advent of Europeans in the area, both human and livestick populations increased.
The high grass of the catchment was grazed down, erosion increased and run-off rates also increased, causing periodic floods. The brushwood barrier system could not deal with the floods and the Njemps turned to pastoralism. Severe overgrazing, drought and locust invasions led to a food crisis in the late 1920s. In the 1930s the colonial administration began considering the possiblity of irrigation, and a formal study was made in 1936, although nothing was done for some years.<ref name=chambers1973/>

The Perkerra irrigation scheme was launched in 1952 during the [[Mau Mau Uprising|Emergency]].<ref name=chambers/>
Construction began in 1954.<ref>{{cite web
|url=http://softkenya.com/water/irrigation-in-kenya/
⚫
|title=Irrigation in Kenya
|work=SoftKenya
|accessdate=2012-04-11}}</ref>
Detainees made the roads and prepared the land for irrigation.
The project was rushed, expensive to implement and maintain, with little in return.
There were difficulties raising crops and difficulty selling them.
Many of the tenant farmers who were settled on the project later left.
By 1959 it was decided to close the scheme, which had only 100 families, but this was changed to continuing minimal operations. In 1962 the scheme was expanded, and by 1967 there were 500 farming houses, although subsidies were still needed.<ref name=chambers/>
The Perkerra irrigation scheme now supports about 670 farm households.
Total potential irrigation area is {{convert|2340|ha|acre}} but only {{convert|810|ha|acre}} has been developed for gravity furrow irrigation and of that {{convert|607|ha|acre}} is being cropped due to a shortage of water.
Total potential irrigation area is {{convert|2340|ha|acre}} but only {{convert|810|ha|acre}} has been developed for gravity furrow irrigation and of that {{convert|607|ha|acre}} is being cropped due to a shortage of water.
In the past the main crops were onions, chilies, watermelons, pawpaws and cotton. Maize was introduced in 1996 and has proved easier to market.<ref name=Natirrig/>
In the past the main crops were onions, chilies, watermelons, pawpaws and cotton. Maize was introduced in 1996 and has proved easier to market.<ref name=Natirrig/>
Line 37: Line 62:
|publisher=Kenya Agricultural Research Institute
|publisher=Kenya Agricultural Research Institute
|accessdate=2012-04-11}}</ref>
|accessdate=2012-04-11}}</ref>

==Erosion and water shortage==

With little plant growth on most of the lower levels, the soil erodes easily and much sediment is deposited in Lake Baringo.
Between 1972 and 2003 the depth of the lake has fallen from {{convert|8|m}} to {{convert|2.5|m}}.<ref name=Onyando/>
The lake has contracted from {{convert|160|km2}} in 1960 to {{convert|108|km2}} in 2001.
It is becoming saline, and fish stocks are declining.
A 2010 study indicated that the river was becoming seasonal. The study recommended implementing a mandatory reserve, or environmental flow.
It was thought that the Chemususu dam project on one of the main tributaries of the Perkerra, due to be commissioned in 2011, would mitigate the effect of the reserve on water users while ensuring that the river did not dry up altogether.<ref name=Akivaga/>


==References==
==References==
{{reflist |refs=
{{reflist |refs=
<ref name=Akivaga>{{cite journal
|url=http://www.weap21.org/Downloads/Akivaga_et_al.pdf
|journal=International Journal of the Physical Sciences |volume=5 |issue=16 |pages=2441-2449 |date=4 December, 2010
|title=Impact of introducing reserve flows on abstractive uses in water stressed Catchment in Kenya: Application of WEAP21 model
|first1=Erick Mugatsia |last1=Akivaga |first2=Fred A. O. |last2=Otieno |first3=E. C. |last3=Kipkorir |first4=Joel |last4=Kibiiy |first5=Stanley |last5=Shitote}}</ref>
<ref name=chambers1973>{{cite web
|url=http://opendocs.ids.ac.uk/opendocs/bitstream/handle/123456789/115/rc180.pdf?sequence=2
|title=MWEA: An Irrigated Rice Settlement in Kenya
|first1=Robert |last1=Chambers |year=1973
|accessdate=2012-04-11}}</ref>
<ref name=chambers>{{cite book
|url=http://books.google.ca/books?id=dsTBkFnYjRYC&pg=PA6 |page=6
|chapter=Learning from project pathology: The case of Perkerra
|title=Ideas For Development
|first=Robert |last=Chambers
|publisher=Earthscan |year=2005 |ISBN=1844070883}}</ref>
<ref name=Natirrig>{{cite web
<ref name=Natirrig>{{cite web
|url=http://www.nib.or.ke/index.php?option=com_content&task=view&id=35&Itemid=48
|url=http://www.nib.or.ke/index.php?option=com_content&task=view&id=35&Itemid=48
Line 45: Line 95:
|publisher=National Irrigation Board
|publisher=National Irrigation Board
|accessdate=2012-04-11}}</ref>
|accessdate=2012-04-11}}</ref>
<ref name=Onyando>{{cite journal
|url=http://www.ingentaconnect.com/content/klu/warm/2005/00000019/00000002/00002706
|title=Estimation of Potential Soil Erosion for River Perkerra Catchment in Kenya
|last1=Onyando |first1=J. |last2=Kisoyan |first2=P. |last3=Chemelil |first3=M.
|journal=Water Resources Management |volume=19 |issue=2 |date=April 2005 |pages=133-143 |publisher=Springer}}</ref>
}}
}}
{{Rivers of Kenya}}
{{Rivers of Kenya}}

Revision as of 18:38, 11 April 2012

Perkerra River
Physical characteristics
Mouth0°32′05″N 36°05′33″E / 0.534632°N 36.092491°E / 0.534632; 36.092491
 • elevation
980 metres (3,220 ft)

The Perkerra River is a river in the Great Rift Valley in Kenya that feeds the freshwater Lake Baringo. It is the only perennial river in the arid and semi-arid lands of the Baringo District.[2] The Perkerra river supplies water to the Perkerra Irrigation Scheme in the Jemps flats near Marigat Township, just south of the lake.[3]

Catchment

The river has a catchment area of 1,207 square kilometres (466 sq mi).[1] It rises on the western wall of the Rift valley at 8,000 feet (2,400 m), dropping down to 3,200 feet (980 m) at its mouth on the lake.[4] The catchment area has steep slopes on the hillsides, flattening out lower down.[1] Most of the water comes from the hill slopes, where annual rainfall is from 1,100 millimetres (43 in) to 2,700 millimetres (110 in). The region around the lake is semi-arid, with annual rainfall of 450 millimetres (18 in) and annual evaporation rates of 1,650 millimetres (65 in) to 2,300 millimetres (91 in).[5]

Land use changes

In the late 1800s the alluvial plains near the lake were occupied by the Njemps people, an ethnic group related to the Maasai. They used a brushwood barrier to raise the level of the river and let the water flow over the flat ground. The barrier would be destroyed by the seasonal floods, needing to be replaced, but the system was stable. With the advent of Europeans in the area, both human and livestick populations increased. The high grass of the catchment was grazed down, erosion increased and run-off rates also increased, causing periodic floods. The brushwood barrier system could not deal with the floods and the Njemps turned to pastoralism. Severe overgrazing, drought and locust invasions led to a food crisis in the late 1920s. In the 1930s the colonial administration began considering the possiblity of irrigation, and a formal study was made in 1936, although nothing was done for some years.[4]

The Perkerra irrigation scheme was launched in 1952 during the Emergency.[3] Construction began in 1954.[6] Detainees made the roads and prepared the land for irrigation. The project was rushed, expensive to implement and maintain, with little in return. There were difficulties raising crops and difficulty selling them. Many of the tenant farmers who were settled on the project later left. By 1959 it was decided to close the scheme, which had only 100 families, but this was changed to continuing minimal operations. In 1962 the scheme was expanded, and by 1967 there were 500 farming houses, although subsidies were still needed.[3]

The Perkerra irrigation scheme now supports about 670 farm households. Total potential irrigation area is 2,340 hectares (5,800 acres) but only 810 hectares (2,000 acres) has been developed for gravity furrow irrigation and of that 607 hectares (1,500 acres) is being cropped due to a shortage of water. In the past the main crops were onions, chilies, watermelons, pawpaws and cotton. Maize was introduced in 1996 and has proved easier to market.[2] The Kenya Agricultural Research Institute has a research center in Marigat Township that complements the irrigation scheme.[7]

Erosion and water shortage

With little plant growth on most of the lower levels, the soil erodes easily and much sediment is deposited in Lake Baringo. Between 1972 and 2003 the depth of the lake has fallen from 8 metres (26 ft) to 2.5 metres (8 ft 2 in).[1] The lake has contracted from 160 square kilometres (62 sq mi) in 1960 to 108 square kilometres (42 sq mi) in 2001. It is becoming saline, and fish stocks are declining. A 2010 study indicated that the river was becoming seasonal. The study recommended implementing a mandatory reserve, or environmental flow. It was thought that the Chemususu dam project on one of the main tributaries of the Perkerra, due to be commissioned in 2011, would mitigate the effect of the reserve on water users while ensuring that the river did not dry up altogether.[5]

References

  1. ^ a b c d Onyando, J.; Kisoyan, P.; Chemelil, M. (April 2005). "Estimation of Potential Soil Erosion for River Perkerra Catchment in Kenya". Water Resources Management. 19 (2). Springer: 133–143.
  2. ^ a b "Perkerra Irrigation Scheme". National Irrigation Board. Retrieved 2012-04-11.
  3. ^ a b c Chambers, Robert (2005). "Learning from project pathology: The case of Perkerra". Ideas For Development. Earthscan. p. 6. ISBN 1844070883.
  4. ^ a b Chambers, Robert (1973). "MWEA: An Irrigated Rice Settlement in Kenya" (PDF). Retrieved 2012-04-11.
  5. ^ a b Akivaga, Erick Mugatsia; Otieno, Fred A. O.; Kipkorir, E. C.; Kibiiy, Joel; Shitote, Stanley (4 December, 2010). "Impact of introducing reserve flows on abstractive uses in water stressed Catchment in Kenya: Application of WEAP21 model" (PDF). International Journal of the Physical Sciences. 5 (16): 2441–2449. {{cite journal}}: Check date values in: |date= (help)
  6. ^ "Irrigation in Kenya". SoftKenya. Retrieved 2012-04-11.
  7. ^ "KARI Perkerra". Kenya Agricultural Research Institute. Retrieved 2012-04-11.
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