WATER SUPPLY AND SANITATION SECTOR REFORM PROGRAMME European Union Federal Republic (WSSSRP) of

Integrated Water Resources Management in Nigeria

Hadejia-Jama’are Komadugu Yobe Basin (semi-arid north) Cross River Basin (humid south) Bart J.M. Goes ([email protected]), IWRM Project Presentation for ‘AH K’ Hydrologists, Free University, Amsterdam, Netherlands

April 8th, 2010

Content 1) Introduction Nigeria, Yobe and Cross River basins 2) Hadejia-Jama’are Komadugu-Yobe Basin: overview, regional IWRM issues 3) Institutional structure in water sector 4) IWRM Project for Yobe Basin 5) Groundwater management Damaturu 6) Impact of dams on river flow 1 Introduction to Nigeria

Zuma Rock, near Abuja (capital)

Yobe and Cross River basins (basins in which IWRM Project works) Yobe and Cross River basins compared Attributes HJK Yobe Basin (Nigeria) Cross River Basin (Nigeria) Surface basin [km2] ~179,000 ~59,000 Population (106) 15-20 10-15 Ethnic groups ~2 ~9 Rainfall (mm/y) 350-1,300 1,000-3,500 Mean river flow (109m3/y) ~4.5 50-60 River flow controlled? Yes (2 dams, 1 proposed) No Formal irrigation [ha] ~20,000 ~1,000 Hydrogeology Basement Rock (~35%), Shales (~60% ), sedimentary (~65%) Basement Rock (~15%) Groundwater issues Level decline sedimentary, Borehole siting in shale shallow pollution dominated areas difficult States/provinces 5 (+4) 8 (+1) River Basin Development 2 3 Authorities Basin wide stakeholders forums? yes no 2 Hadejia-Jama’are Komadugu Yobe Basin

Yobe River (Geidam) Intro HJKY Basin – elevation & rivers Intro HJKY Basin – rivers Intro HJKY Basin – annual river flow (106 m3) & geological boundary Jama’are River in upstream Basement Complex area during wet season (draining river) Jama’are River (Bunga Bridge) during dry-season Intro HJKY Basin – river water uses: (in)formal irrigation, urban, Ramsar site, floodplain Surface water intake (6) Kano City downstream of Challawa Dam in dry season, provisional bund in river to raise water level for intake Wet-season flood rice farming Hadejia-Nguru Wetlands (Gashua) Fishermen in Hadejia-Nguru Wetlands (Likori) Informal rice field irrigation from Yobe River (near Damasak) Hand dug watering hole for cattle in Lake Chad area (Kwarildem) Regional Water Management issues HJKY Basin WM Issues HJKY Basin – decline in river stage data Regional water management issues HJKY Basin (or ‘triggers’ for IWRM) • surface water demands exceeding mean river flow • river channel blockages hampering the flow of water to downstream users • impact of large upstream dams • groundwater level decline in certain parts of the basin • potential impact of a new large dam (construction on hold) • decline in hydrometric network • little/no attention for groundwater data & management • a complex institutional structure in the water sector 3 Institutional structure in water sector

Stakeholder Consultative Forum on HJK Yobe Basin, Kano 21-22 May, 2009 Institutions – 2 River Basin Development Authorities water regulator (dams operation) & water user (large irrigation projects) Institutions – 5 (or 8?) States each with: a) Ministry of Water Resources, b) Water Board/Cooperation, c) RUWASA, d) Ministry of Agriculture, e) Agricultural Dev. Programs Other organisations on Water Management in the basin

• HJK Yobe - Trust Fund: implementation of WM measures 2007-11 (financially supported by 6 States & Federal Gov.) • Donor supported projects (DFID, EU, IUCN) • Stake Consultative Forum = IWRM in practise but: a) no legal status b) no budget (depends on donors) c) leadership needs strengthening Institutions – proposed reform under Water Resources Bill River Basin Development Authorities  Irrigation Management Authorities (water user) Institutions – proposed reform under Water Resources Bill one River Basin Management Commission (surface and groundwater regulator) 4 IWRM Yobe Basin Project

A day at the office (IWRM Yobe Project , Damaturu) Integrated Water Resources Management – IWRM some key principles

• manage water according to hydro(geo)logical boundaries • involve all stakeholders • separate water regulator from water user • address both surface and groundwater • take into account the environment • water resources database as a basis for informed water management • IWRM requires ‘triggers’ or regional water issues Situation at start of IWRM Project

Original Project plan was a bit outdated: • Planned support to River Basin Management Commission not possible because delay in acceptance of National Water Bill • Many water plans already available for basin, why develop a new one? • Rehabilitation hydrometric network already ongoing (TF, IUCN)

Sustainability: how to make a long-term impact with a short (~1.5 years) Project? Making IWRM building blocks Activities that will hopefully still be useful after 5 years : 1. Capacity building (counterparts & trainings) 2. Complement hydromet network activities (e.g. ‘ADCP’ for river flow, ‘divers’ for groundwater level) 3. Database development & sharing (river flow, groundwater pilots, formal irrigation projects, ..) 4. Examples of data analyses for water management 5. Upgrade existing (IUCN-HNWCP) river flow and water uses model for informed planning 6. Institutional strengthening (Trust Fund, Stakeholders Consultative Forum) Yobe river flow database: 51 stations with number of years (850 data years in total over period 1958-2008) River gauging – Acoustic Doppler Current Profiler Use of river gaugings – river stage into discharge

Bunga Bridge - Jama'are River (downstream of Kafin Zaki, proposed dam site) - Rating Curves

10

94

8 96

94 95 6 93 95 96 98 93 97 1995-1998 rating equations: River LevelRiver[m] 94 (1) H>0.5 & H=<7.7 Flow = 4*(H-0.5)^2.5 4 95 96 (2) H>7.7 Flow = 1.55*(H-0.5)^2.98 95 H = river level 93

2 05

05 0 0 200 400 600 800 1000 1200 1400 River Flow [m3/s]

river gaugings 1993-1994 curve 1995-1998 curve Outcome of ADCP River gauging – Gashua

Outcome: detailed 2D velocity profile Total discharge 4 profiles in ~30 minutes Pilot groundwater databases: Yobe & Cross River 5 Groundwater management Damaturu

Damaturu, water vendors filling water carts from underground tank near borehole Pilot groundwater databases Yobe – locations Overview of groundwater work

• Means: building and analysing a database • Partners: Ministry of Water Resources, Water Board, RUWASA and UNIMAID • Database building: fieldwork on water quality, GPS, water level (~4 weeks), search archives (pumping tests, litho logs, etc.), data entry • Data analyses: GIS maps, water balance calculation, reporting Pilot groundwater database Damaturu: 223 water points Pilot groundwater database Damaturu: water uses

Public water supply Damaturu

• Attributes public boreholes: 4 l/s, 6 hours pumping per day, 40% transmission losses in water supply • The ~87 existing public boreholes are enough for basic water supply of the ~ 100,000 inhabitants (40 l/d) • Still >50% of population depends on commercial water vendors because: i) half of public boreholes not active (maintenance, delayed commissioning, diesel for pumps), ii) poor revenue generation (metering), iii) large private underground tanks hamper equitable piped water supply Large private underground tank taking all public water Pilot groundwater database Damaturu: aquifers Pilot groundwater database Damaturu: fluoride map

Attributes of high (>1.5 mg/l) Fluoride points Fluoride [mg/l] No data 125 <1.5 93 1.5-5 2 5-10 2 >10 1 Total 223 • In eastern and northeastern part of Damaturu • Deeper boreholes in ‘Chad-B’ aquifer (90-160 m-bs)

Relation with other elements • Fair relation: high: Ph (8-9), low: Ca (≤10 mg/l), hardness

(≤25 mg/l), NO3 (≤2.5 mg/l), Mn (≤0.2)

• No/unclear relation: EC, Na, Mg, K, Cr, Cl, SO4, 2+ - Fluorite mineral dissolution: CaF2 ↔ Ca + 2F So dissolution generally takes place when low [Ca2+] Solution? Reduce [F-] by increasing [Ca2+] (e.g. add gypsum) (based on Appelo & Postma, 2005) Pilot groundwater database Damaturu: summary map Diver installation for automatic groundwater level monitoring 6 Impact of dams on river flows

Releases from Challawa Dam into System Data analyses - impact of dams on river flow Data analyses - impact of dams on annual river flow Cumulative annual flow Bunga (uncontrolled) versus Wudil (controlled)

45 1964-73 (pre-): Wudil = 0.95 x Bunga (R2=99%) 40 1979-89 (post-Tiga Dam): Wudil = 0.64 x Bunga + 6.8 (R2=100%) 35 1974-78: filling up of Tiga Reservoir 1989 30

25 1979

20 1973 15

10 Cumulative annual flow at Wudil [109m3]...... Wudil at flow annual Cumulative 5

1964 0 0 5 10 15 20 25 30 35 40 45 Cumulative annual flow at Bunga [109m3] Data analyses - impact of dams on annual river flow Cumulative annual flow Bunga (uncontrolled) versus Hadejia (controlled)

16 1990 1964-73 (pre-Tiga Dam): Hadejia = 0.34 x Bunga 2 14 (R=100%) 1979-90 (post-Tiga Dam): Hadejia = 0.37 x Bunga - 1.03

12 1974-78: filling up of Tiga Reservoir

10 1979

8

1973 6

4

2 Cumulative annual flow at Hadejia [109m3]...... Hadejia at flow annual Cumulative

1964 0 0 5 10 15 20 25 30 35 40 45 50 Cumulative annual flow at Bunga [109m3] Data analyses – river flow reduction Wudil-Hadejia Flow arriving at Hadejia (downstream) given flow at Wudil (upstream) Data analyses - impact of dams on dry-season river flow Data analyses - impact of dams on dry-season river flow Daily flow Hadejia 1967/68 (pre Tiga & Challawa Dams) Data analyses - impact of dams on dry-season river flow Daily flow Hadejia 1995/96 (post Tiga & Challawa Dams) Data analyses - impact of dams on dry-season river flow Annual & dry-season flow Hadejia 1964-2001 Consequences of unnatural dry-season flows

• Channel blockages because: a) river beds no longer dry out so Typha and other weeds get water all year round, b) reduced peak flows to flush the channels • Excess water in Marma Channel • Minimal contribution from Hadejia to Yobe River • Waste of water especially in second half of dry- season Consequences dry-season flows – Hadejia-Nguru Wetlands Weed blockages in lower Burum Gana River, dry season Excessive floods Hadejia-Nguru road near Marma Channel, 2005 wet-season Thank you for your attention

Repairing a puncture on a cart of a water vendor, Damaturu