The contested causes of environmental change (Via the Usangu and - - PowerPoint PPT Presentation

School of International Development University of East Anglia

Bruce Lankford Talk for the British Tanzania Society at SOAS 10th Oct 2016

Are the rivers in Tanzania at risk of drying up? The contested causes of environmental change

(Via the Usangu and Great Ruaha case study)

Photo by B Lankford, 2000, Ruaha River just upstream of Usangu Wetland

Expert knowledge/science/authority and public sociology (after Burawoy, 2004) regarding complex and long term environmental change in an area the size of ‘Wales’ but:

• Risk of criticising others and placing myself as expert
• Risk of contradiction; I too am facing ‘gaps’ in knowledge
• Risk of painting a ‘tableau’ of fixed figurines, conditions

and drivers.

• Not been to Usangu since 2005 except for one brief visit 5

years ago.

• Asked to reflect today as a 35 min public lecture.
• This room contains many people with views, more recent

and deeper knowledge.

• Can only hint at ‘recommendations’
• Looking forward to the discussion.

Provisos!

1) Semi-arid area (Pe~650 mm; ETc 1900 mm) and ratio of irrigable land to water is weighted to the former. Excluding the

peak flows of >150 cumecs in Jan-March, water supply during the rest

• f

the year can feed approximately 80-90,000 ha

• f

supplementary irrigation, and ~8,000 ha during the dry season. The irrigable area in Usangu can be estimated at 5 to 10 times this.

2) Increasing opportunities to withdraw small volumes of water that cumulatively add up. Via informal gravity intakes and small

<3 to 5 kW diesel pumps with ~5-8 m suction.

3) Misinterpreting causes/impacts of hydrological change & drawing up seemingly-sensible/doable but flawed or blanket interventions that take us in unhelpful directions.

E.g. fixed water rights, intake designs, drip, types of institutional support.

Are rivers in Tanzania at risk of drying up? In a word: Yes (there is a risk).

Location of case study in Tanzania – Gt Ruaha or Usangu Basin

Area = 22,000 sq km Area of Wales = 20,761 sq km

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• r

• j

IMAGE OF 14TH AUGUST1994

Runoff shared by many sectors

The sharing of water Watershed of the Usangu escarpment

Smallholder irrigation and livestock/fishing Typically less than 500 ha, and sometimes fed by more than one intake, traditional or ‘modernised’

Large irrigation systems, > 3000 ha

Ecosystems & livelihoods in Ihefu wetland - Usangu Ecosystems in the Ruaha National Park Hydropower for Tanzania: Kidatu dam

Downstream water demands in the basin

20,000 to 40,000 ha of irrigation varies according to rainfall. Measured in 1999 to 2005

Power cuts are due to dams running out of water due to droughts and upstream abstraction of irrigation water

Interpreting plausible sanctioned causes of Ruaha change

Wetland undergoing change due to upstream abstraction by irrigation and livestock impacts Excessive livestock numbers causing soil compaction, faster runoff and reduction in wetland’s ‘sponge’ ability to store water Deforestation in highlands causing faster runoff response and lower baseflows of rivers. AND/OR Change in rainfall due to climate change Increasing area of rice irrigation ET; higher volumes consumed combined with narrative about inefficient irrigation.

Critically investigated complexity causes of Ruaha change Power-cuts were fault of dam operation. Excessive rapid draw-down of dam storage under political pressure to generate more/ cheaper electricity. = inability to bridge dry periods. Past flood events deposited detritus; wetland channels blocked; expands and evaporates more; leading to lower flows at exit for a given inflow of water; fewer large fauna clearing passages Livestock numbers might cause local environmental change but insufficient to alter catchment hydrology at the volumes seen. Difference from reported high numbers of game reported historically.

Insufficient evidence of deforestation affecting

• runoff. Alpine upland grass ecology

Rainfall is semi-arid; highly variable

Dynamic mosaic of wet and dry season irrigation ET; variable and unmeasured efficiencies; water recycled; dry season impact is relatively greater; role of intake modernisation and water rights.

Water Resources Engineering Programme (WREP, UDM)

Power cuts during 1990 to early 2000s were due to a combination of a) political pressure to generate electricity/revenue but not conserve water behind Mtera storage dam and b) the two dams Mtera and Kidatu not being

• perated as a single unit after turbines were installed at Mtera in 1998

Similarities with lake Albert and Owen Falls dam in 2005

http://reliefweb.int/report/kenya/usda-low-water-levels-observed-lake-victoria

Zero flows in RNP and HEP cuts not directly connected

0.1 1.0 10 100 1000

In a dry year, river still flows in the wet season Supply and demand (m3/sec) Time

Dec Jan Dec Jan Dec Jan Dec Jan

Supply hydrograph 1970 to 1990 Supply hydrograph, 1998

• nwards – difference due

to upstream abstraction Note log scale

Gross Inflow 3700 Mm3 Beneficial process depletion 478 Mm3 Beneficial non- process depletion (Wetland evaporation) 379 Mm3 Non-beneficial depletion (irrigation losses) 343 Mm3 Committed (to hydro-power, which also serves Ruaha National Park and Kilombero Sugar) Outflow 2130 Mm3 Available 1200 Mm3 Groundwater 370 Mm3 To East African Rift Valley geology and fault Livestock 3.5 Mm3 Domestic 2.5 Mm3 Irrigation 472 Mm3 Net Inflow 3330 Mm3

Basin water accounting = human- process depletion / net inflow (478 + 343) / 3330 = 25% So ¼ of water (in 2005) consumed upstream of Usangu wetland

RIPRWIN report on Mtera, 2005

“These findings lead to the conclusion that the problems at Mtera and Kidatu may be attributed more to water management at Mtera than on any other factor including drought. The control and regulation of abstractions operations that are conducted in the Great Ruaha River Catchment upstream Mtera reservoir are more important to keeping the level of the Utengule swamp high enough to sustain flow in the Ruaha National Park and therefore more beneficial to the Park than to Mtera

• reservoir. The rainy season during December to April is the best for

filling the Mtera dam and not the dry season. From these findings, RBWO are convinced that if the reservoirs are

• perated modestly and according to prudent operation rules these

crises and events can be minimized considerably. “

Zero flows in RNP and HEP cuts not directly connected

More recent errors in science?

Next few slides – comparing surveys from the World Bank with those undertaken by SMUWC an RIPARWIN

19

Satellite data shows the staggering expansion

• f informal irrigation in the upper GRRC

Large-scale schemes of Mbarali, Kapunga and Madibira Planned small-scale schemes Unplanned irrigation development

1998 2013

Source: World Bank Group, unpublished report (2015)

20,000 to 40,000 ha of irrigation varies according to rainfall. Measured in 1999 to 2005

Next few slides – responding in two ways to concerns about excessive upstream consumption by irrigation. 1) Improving the efficiency of irrigation 2) Regulating water demand via the application of water rights.

Top-enders Tail-enders

October 11, 2016

Collective arrangements Engaging with irrigators

Water management for a rice nursery at the top-end

• f the irrigation system

Water management for a rice nursery at the tail-end

• f the irrigation system

Replacing this type of ‘support ‘thinking

“Farmers must be trained on soil and water technologies to enhance crop production and food security”

• ASARECA. 2006 Maputo Workshop statement www.asareca.org/swmnet

.

With this kind of support thinking:

What training, institutional and technological needs arise when we bring farmers from top- and tail-end systems together while handing them responsibility to allocate water between themselves within irrigation systems, and between systems and to downstream users? Engaging with irrigators

Water rights – World Bank Project RBMSIIP, 1998-

IWRM; formal water rights, expressed in flow rate for abstractors of water for productive uses – consists of an application fee of $40, then $35 flat rate/year, then $0.035 per m3 per year. Rationale for introducing water rights:

• “enhancement of water fees... as an incentive for water

conservation... and as a source of funds for water regulation activities, catchment conservation and water resources monitoring”

• “economic instruments include water pricing, charges,

penalties and incentives to be used to stimulate marketing mechanisms and serve as an incentive to conserve water..”

October 11, 2016

Local artisans and traditional intakes – consider form and function

Donor improved irrigation intakes in Southern Tanzania These intakes enable the first irrigators to take all of the water when river flows are less than the intake flow capacity

Fault-lines & problems with water rights system

New water rights (e.g. 200 l/sec) do not recognise customary water rights Poorly accommodate swings in water supply due to seasonality Not tied to actual water taken because no measuring structures were/are in place. (Record of measuring difficult) Not related to maximum discharge capacities of the new intakes Not related to the varying command area of irrigation systems Were not, when cumulatively added to other water rights, related to the overall supply in the river system. Could not be requested by those who could not abstract water – therefore fisherpeople and cattle keepers Design of irrigation demand, intakes and weirs promotes fixed maximum abstraction Upstream users continue to take fixed amount In dry season, abstraction proportionally becomes larger and larger - drying out the river downstream

Proportional management of water

Users expect variable climatic conditions

• Introduce proportional property rights?
• Proportions need to be clarified and examined
• Supported & legitimised via water rights
• Accepted by river communities
• Enabled & encouraged via technology -

proportional abstraction intakes?

Is the answer to utilise concrete or metal proportional dividers?` Fixed Fixed Adjustable Fixed

Political ecology interpretation of science solutions | Political economy of environment-development research

Professionals/academics hold onto sanctioned interpretations of causality

• f environmental change. While offering scientific plausibility, are these

interpretations sufficient? Proposed ‘solutions’ even more tied to professional & political practices and norms, less to sanctioned analyses of causality Powerful political players (gov, non-gov, individuals) have vested interests such as owning irrigated plots, mediating irrigation change, forcing extra power generation from stored water, etc. Less powerful individually but numerous farmers seek water for irrigation. Aided and abetted by a) lack of water metrics, literacy and numeracy and b) political economy of ‘env-dev research’; predominantly short-term, rarely inter/multi disciplinary, sanctioned normative calls (ESPA)

Social constructivism, critical realism, political ecology (Forsyth 2001, 2003; Bryant and Bailey, 1997; Demeritt, 1994); how consensus/knowledge about freshwater problems is co-constructed by actors; where ex-officio authority & training (leading to Chamber’s normal professionalism) plus social, and linguistic contexts shape complex biophysical trends and events into identifiable “problems” and “processes” (Forsyth, 2003) leading to ‘naturalised solutions’ (Boelens, 2012)

Any questions? In a hot climate, irrigation is a cool topic…

Sanctioned solutions for returning Ruaha to perennial flow

Build new dams; raise dam walls (debate at international level) Enclosures or designate special status; (Ramsar contemplated but now part of RNP) Livestock taxes. Boundaries and enclosures (already done RNP extended) Enclosures; parks; rules about forest logging Improve irrigation efficiency; price water; privatise large-scale irrigation systems

Integrated synoptic catchment solutions:

• IWRM/Dublin Ps
• Water rights
• Payment for ES
• District planning

Naturalised integrated solutions in that these seem the natural way forward – but will they work? (How tailored are these pan-basin approaches to local trajectories and solutions?)

Sector solutions

10 MW = 50-80 ha (2015) 280 MW of Mtera/Kidatu = 2000 ha plant

Solar power disconnects hydro from variable water supplies

Kidatu 204Mt & Kid Kihansi 180 284 Mtera 80 Pangani 68 Hale 21 NyM 8 561 51%