Feeding a city by repairing its water and its streets
A data-checked case for greening Lomé with edible, guild-planted trees and rehabilitating the Bè Lagoon area, and beyond it the much larger mangrove restoration this first study should open up in the coastal lagoons east of the city. Every figure below is sourced.
1. Where this is
The pilot starts in the heart of the city, at the Bè Lagoon area and its surrounding streets. Nearby, in the coastal lagoons east of Lomé, lies the region's real mangrove forest, much larger and much diminished. The map shows both. Switch the basemap to satellite to see the real ground.
This map is the bird's-eye view: it opens on live satellite imagery of the city, the lagoon, and the mangrove complex; use the layer control to switch to the street map. Markers are placed at approximate coordinates for orientation, not surveyed boundaries. On-the-ground photos: Lomé on Wikimedia Commons · Lake Togo · Bè Lagoon on Google Maps.
Where the pilot starts: the Bè Lagoon area, in the city. Lomé's lagoon is three linked urban lakes, Lac Bè (29 ha), Lac Est (31 ha) and Lac Ouest (20 ha), about 80 ha in total, in the heart of the agglomeration: a working fishery, yet heavily burdened by untreated sewage, solid waste and pesticide-laden runoff.11 This is where the first rehabilitation and greening happen.
The larger prize: the mangroves east of the city. The coastal lagoon system beyond Lomé (Lake Togo, Lake Boko, the Aného lagoon and the Gbaga channel, fed by the Mono, Haho and Zio rivers) holds the region's real mangrove forest.3 Land-cover analysis puts it at about 996 ha in 1986 falling to ~742 ha by 2014, and it is widely described as declining from ~1,000 ha toward ~112 ha by the late 2010s.3 Restoring it is the bigger opportunity this pilot should encourage (Section 6).
So the pilot starts in Lomé, where the applicant (the District Autonome du Grand Lomé) has clear authority and clear need, and is built so its nurseries, stewardship model and survival data open the way to the larger mangrove restoration nearby, the piece that carries the strongest international climate-finance case.
2. The city, in numbers
| Measure | Value |
|---|---|
| Grand Lomé population (2022) | 2,188,376 1 |
| Growth 2010 → 2022 | 1.57M → 2.18M 2 |
| Share of Togo's 8.10M people | ~27% 1 |
| Area (District Autonome) | 425.6 km² 2 |
| Communes | 13 2 |
| Water body | Size |
|---|---|
| Lac Bè (in city) | 29 ha 11 |
| Lac Est (in city) | 31 ha 11 |
| Lac Ouest (in city) | 20 ha 11 |
| Lake Togo (SE) | ~64 km² 13 |
| Zio River length | ~87 km 13 |
Grand Lomé's area is 425.6 km² per the District (some sources give 373 km²)2; the Zio is Togo's third-longest river, about 87 km, with its mouth at Lake Togo.13
3. The climate that decides which trees live
Lomé sits in the Dahomey Gap, a quirk where the West African coast here is drier than the land just inland: the shoreline faces south-east while the monsoon rains arrive from the south-west, so the coast stays semi-arid.7 Köppen class Aw (tropical savanna). Station records put annual rainfall near 800–900 mm; NASA's satellite-reanalysis record for the grid cell reads higher (~1,100 mm), a known coastal over-read. Following an observation-first rule, the station total is the truth and the reanalysis is used for the shape of the year, which both agree on: two wet seasons with a dip between them.
Solar resource
≈ 4.3–5.3 kWh/m²/day (mean 4.85), highest in April and November, lowest in the cloudy July–August dip.8 Strong enough to (a) drive high evapotranspiration, new trees will need water in the dry season, and (b) power solar nursery irrigation pumps cheaply.
Humidity & wind
Mean humidity 83% (75% in January to 88% in July).8 Onshore wind peaks at ~4 m/s in July–August, carrying salt spray inland, a reason for salt-tolerant species and windbreaks near the shore.
4. The challenges the trees are meant to answer
Flooding
In 2010, Lomé recorded 365 mm of rain in June against a 1971–2000 normal of 184 mm, and 205 mm in September against a normal of 64 mm, a ~40-year return-period event.5 Water reached 20–35% of areas that do not normally flood, concentrated in the "two cordons," the low strip between the lagoon and the sea, the same ground the Bè lagoon sits in.5 Nationally the floods killed 21 people and destroyed roughly 50,000 homes.6 A caveat worth stating plainly: on a flat coastal sand plain with a high water table, trees help mainly through canopy interception, root infiltration and bank-holding, a genuine complement to drainage, not a substitute for it.
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A degraded lagoon and a lost mangrove
Lomé's urban lagoon is a fisheries resource for the surrounding population, yet it absorbs the city's untreated sewage, septic discharge, household waste and agricultural runoff.11 Forty kilometres east, the mangroves that anchor the coast's fisheries and buffer its shoreline have lost the better part of their extent to cutting, siltation and dam-altered flows.3
Heat and water stress
High, humid heat year-round (Section 3), plus over-exploited coastal groundwater with saline intrusion, argue for drought- and salt-tolerant species near the coast and for capturing stormwater at each tree rather than irrigating from wells.
5. Why mangroves, and why edible guild-forests, actually help
Mangroves (the larger opportunity)
- A 100 m belt can cut wave height by up to 77% in a storm, direct shoreline and settlement protection.9
- Fish catch up to 70% higher in mangrove-adjacent waters, the fishery the lagoon communities live on.9
- Among the most efficient blue-carbon sinks on Earth, ranked second only to coral reefs in ecosystem-service value, which is precisely what makes this component eligible for climate finance.9
Edible streets & pockets (the pilot)
Edible is the concept's best idea and its biggest liability, and the pilot is designed around that tension rather than hiding it:
- Harvest by destruction. In practice people take fruit by breaking branches and throwing sticks, and fight over it. A public fruit tree needs real protection and gets damaged far more than a plain shade tree. The budget funds guards, a neighbourhood-fruit charter, and harvest/pruning training as core lines, not afterthoughts.
- Lone fruit trees die. They are planted in guilds, a fast-growing first layer plus nitrogen-fixers, nurse plants and ground cover (the syntropic-agriculture principle), so the system holds its own moisture and shade instead of needing constant care.
- Back-loaded payoff. Mango and cashew fruit only after 5–8 years, after the funding window. Fast species (moringa, papaya, banana) deliver visible wins in 12–18 months while the slow, high-value trees mature underneath.
- Roadside food safety. Fruit on the busiest, most polluted corridors is a health question, so edible species are kept off them; those streets get non-fruiting shade.
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6. The pilot, costed, and what it opens up
The proposal is the Lomé pilot (~$320k). Below it, as an indicative next step, is the larger mangrove restoration the pilot is meant to encourage. All figures are benchmark-derived planning estimates for local validation, not quotes, in USD with XOF at ≈ 600/USD (the CFA franc is euro-pegged). The strongest single unit cost is the mangrove line: a community project in neighbouring Benin restored mangrove at $1,394/ha using the same species.14
| Stage | What | Scope | Est. cost |
|---|---|---|---|
| Pilot · Lomé | Baselines & monitoring (funded first) | all pilot sites | $40,000 |
| Urban lagoon-edge rehabilitation | ~20 ha | $60,000 | |
| Street trees (guild + guard + 3-yr care) | ~1,500 | $42,000 | |
| Pocket food-forests | 5 sites | $24,000 | |
| Community nurseries | 3 | $57,000 | |
| Staffing, mobilisation, protection & charter | 24 months | $63,000 | |
| Pilot subtotal + 12% contingency | ≈ $320,000 | ||
| Next step · east of Lomé | Mangrove restoration (propagule + hydrology) | 50 ha | $70,000 |
| Channel / hydrological repair | $30,000 | ||
| Fisher co-design (Lacs/Vo), nursery, monitoring, coordination | $95,000 | ||
| Indicative next-step subtotal + 12% contingency | ≈ $218,000 | ||
| Pilot + indicative next step | ≈ $538,000 | ||
Funding fit: the ~$120k mangrove + flood-buffer core of the next-step restoration is the climate/biodiversity-finance-eligible piece (GCF, GEF, BGCI, UN-Habitat); the Lomé pilot splits between municipal seed funding and diaspora/CSR "sponsor-a-tree" units at ≈ $28 (≈ 17,000 XOF) per established street tree. The softest numbers are the per-tree composites; replace them with a real Togolese nursery-and-guard quote first.
Sources
- Togo 5th census (RGPH-5, Nov 2022), definitive results, total 8,095,498; Grand Lomé 2,188,376. INSEED / Togo First. results PDF, INSEED.
- District Autonome du Grand Lomé, area (425.6 km²; alt. 373 km²), 13 communes, growth 1.57M→2.18M. DAGL, Rép. Togolaise.
- Mangrove extent & loss, SE Togo lagoon complex. "Écologie et dynamique spatio-temporelle des mangroves au Togo," VertigO openedition; context Vert-Togo (112 ha); SCIRP land-use study.
- Mangrove restoration cost range (global median ~$8,143/ha). Mongabay; One Earth.
- 2010 flood rainfall & the "two cordons." "Climate change and urban stormwater: vulnerability analysis of the 2010 floods in Lomé," Frontiers in Climate, 2023. article.
- 2010 flood toll (West Africa incl. Togo). FloodList.
- Dahomey Gap dry-coast anomaly; Lomé ~800 mm, Köppen Aw. Dahomey Gap; Climates to Travel.
- Climate normals (rainfall, temperature, humidity, solar, wind), NASA POWER 20-yr monthly climatology 2001–2020 at 6.13°N, 1.22°E. NASA POWER.
- Mangrove ecosystem services, wave attenuation up to 77% (100 m belt), fish catch up to +70%, blue carbon. Review: Ecological & Economic Significance of Mangroves; WRI blue carbon.
- Urban tree cooling, 5–8°C air, up to ~27°C surface, lethal-heat days −23%. WRI; Comms Earth & Environment 2024.
- Lomé urban lagoon, three lakes (Bè 29 ha, Est 31 ha, Ouest 20 ha), pollution. Lab. écologie fonctionnelle; Focus Infos.
- Togo minimum wage (SMIG 52,500 FCFA/month since 2023 ≈ $88; SMAG 38,500 FCFA). Rép. Togolaise.
- Lake Togo (~64 km²) and Zio River (~87 km, mouth at Lake Togo). Lake Togo; Rivers of Togo.
- Community mangrove restoration cost, West Benin ($1,394/ha, Rhizophora racemosa). Agraz-Hernández et al., Restoration Ecology, 2025. article.
Prepared as an evidence brief for the Lomé Ville Nourricière concept. Figures are cited to source; cost figures are benchmark planning estimates for local validation, not quotations. Climate values computed from NASA POWER; open this file in a browser with internet access for the interactive map.