The catchment is divided into eight sub-catchments according to the main river systems namely Macheke, Budzi, Devure, Lower Save East, Lower Save West, Odzi, Pungwe and Upper Save. There are 26 hydrological sub-zones with areas varying from about 100 to 4719 km2
The Save catchment comprises of two major drainage systems, the Save river drainage system and the small drainage systems of the Eastern Highlands. The Save river drainage system comprises mainly of the river it’s self and its tributaries, basically rivers located in the E Hydrological sub zones. The other drainage system comprises of a conglomeration of various rivers namely the Pungwe, Honde, Budzi and Nyamakwavara rivers, in the Eastern Highlands which flow into Mozambique, or rivers located in the F zone.
The Save River rises near Featherstone, some 65 kilometres South-West of Marondera, at an altitude of approximately 1 450 metres above sea level in a 600 mm to 700 mm rainfall area.
It flows South-Eastwards for approximately half of its 400 kilometres length and then Southwards before it joins the Runde River at an altitude of only some 160 metres above sea level, and enters Mozambique.
Up to its confluence with the Runde River, the Save drains a catchment area of some 43 494 square kilometres in which the average rainfall varies from over 1 200 mm per annum at the headwaters of the Odzi and Odzani Rivers to 300 to 400 mm in the lower Save area.
The main tributaries of the Save river are:
(i) In its upper reaches, the Ruzawi river which drains a catchment area of 2 137 square kilometres;
(ii) in its middle reaches, the Macheke and Mwerihari rivers which drain catchment areas of 4 316 and 2 587 square kilometers respectively;
(iii) the Odzi and Devure rivers, which join the main river above the mid and lower Save plain, and which drain catchment areas of 7 333 and 8 224 square kilometres respectively;
(iv) In its lower reaches, the Turgwe and Mkwasine rivers which drain catchment areas of 3 134 and 1 577 square kilometers respectively.
The Pungwe river rises 3 kilometres north-west of Mount Inyanga at an altitude of 2 120 m. It flows in an easterly direction until it crosses the Mozambique border at an altitude of 600 m above sea level. The river has a catchment area of 644 square kilometres and the average annual rainfall in the catchment varies from over 1200 mm at its headwaters to 600 mm at the border.
The Honde river rises at a altitude of 1 440 metres above sea level at Watsomba village in the Tsonzo Purchase Land. The river has a catchment area of 366 square kilometers and the rainfall in the catchment varies from over 1 200 mm at its headwaters to 1000 mm where the river crosses the border.
The Nyamakwarara river rises at an altitude of 1 740 metres above sea level in the Stapleford Forest north of Mutare. The river, which has a catchment area of 220 square kilometers, occupies the same sub-zone as the Honde river and thus has similar characteristics of high rainfall.
The Budzi river rises at an altitude of 1 160 metres above sea level in Whittington Valleys north west of Chipinge, it then drains in a south easterly direction into Mozambique. The river has an approximate catchment area of 600 square kilometers and the rainfall in the catchment varies from over 1 115 mm at its headwaters to 979 mm where the river crosses the border.
The rainfall season of the catchment, as is of the country, stretches from October to April with most of the rainfall being received in February. The period from May to September is typically dry with very little or no rainfalls being received.
Average annual rainfall for the catchment is 899 mm, but geographically ranges from 2 000 mm/year in the Eastern Highlands to around 410 mm/ year in the Low-Veld in the South. The winter season is from April to August, and the hottest and driest period is from September to mid-November. Average annual evaporation for the catchment is 1720 mm/year, but geographically as with rainfall, ranges from 1 200 mm/year in the Eastern Highlands to around 2000 mm/ year in the Low-Veld in the South.
According to the 2002 population census, the Manicaland province, which is the dominant province in the catchment, has a population of 1 566 889. The population density in the Save catchment ranges from 69 people per square kilometre in the Mutare district which is predominantly urban, 41 in the Buhera district which is predominantly rural and 27 in Wedza district which is predominantly a commercial farming area. The urban growth rate has been 4.7 % and rural growth rates 2.7%. Of the nine districts that make up Save catchment three are dominated by urban setups, four rural and two commercial farming.
The major economic activity in the catchment is agriculture. In the Eastern Highlands or Natural region I, which is characterized by very high rainfall, there are large plantations specializing in Forestry, wattle, tea, coffee, deciduous fruits, barley and potato production. The major companies being Tanganda Tea estates, Wattle Company, Border Timbers and Forestry commission. Intensive beef and dairy farming is also practised in this region. The region covers the Pungwe, Odzi and Budzi sub catchments
The major manufacturing industries are located in the City of Mutare and they mostly specialise in the manufacturing of foodstuffs, paper and printing and furniture. Other notable industries are the oil refinery and the car assembly plants.
The major mines in the catchment are Bikita minerals, Redwing, Dawn mine and Dorowa minerals and there are involved in the mining of Lithium, gold and phosphate.
In the catchment, the population growth has impacted on the demand for water resources. A rapid urban population growth has increased demand on treated water supply and sanitation services. In the rural areas, primary water needs have been met mainly from groundwater resources. This demand is expected to increase. Overcrowding in the communal areas coupled with the cultivation of marginal lands and lack of conservation structures has led to severe erosion that has increased the amount of siltation, thereby significantly shortening the life of dams and other small reservoirs.
Irrigated agriculture will continue to dominate the water demands of the catchment and about 240 000ha of land can be made available for irrigation development. Although there is enough land available for irrigation, a mismatch between good dam sites and occurrence of irrigable land may preclude full utilisation of this potential.
Therefore the socio-economic aspects of the catchment are quite challenging hence the need for the development of an integrated approach or framework which will; promote equal access of water to all people and socioeconomic sectors, create an environment that promotes stakeholder participation, create an enabling environment for an integrated approach to land and water resources planning and management, put in place measures that enhance the availability of water resources of suitable quality and quantity where and when it is needed, promote private sector financing in the water sector, develop water pricing policies and mechanisms which recognise water as an economic good.
Socio-economic activities in Save catchment range from industry, mining, urban settlements, tourism to agriculture.