It was a very chilly morning on Monday the 14th of July 2014 when six individuals started their trek up the Dorpspruit river from the confluence of the Dorpspruit and uMsunduzi rivers, near Mussons rapids.
The team comprised Sanele Vilakazi, Siyabonga Ndlovu, Kholosa Magudu, Leeth Singh, Sashin Naidoo and Adowa Awuah who walked about 11kms along the Dorpspruit river over four days.
The Dorpspruit river is one of the major tributaries of the uMsunduzi river which is a major trunk stream of the city of Pietermaritzburg in terms of economic importance. The walk was undertaken to assess the state of the rivers’ health and to also promote DUCT’s river stewardship project which aims to promote the adoption of certain stretches of the river by neighbouring landowners. The findings of this walk will be used to assist in carrying out the above mentioned project forward and further assisting willing landowners to solve certain problems along the river stretch.
After the walk, all those that were involved in the walk itself admitted to having a much clearer picture on the health of the river. This walk has allowed us to carry out a whole host of groundtruthing exercises/initiatives using a newly acquired mobile mapper (Spectra mobile) sponsored by the N3TC, through the Midlands Conservancies Forum. This great tool has allowed us to input a host of environmental data that we picked up as we walked the channel. With the tool we were able to precisely pin-point our position along the river and the position of other significant features at which we felt needed to be taken note of. All of the data collected by this mobile mapper is to be collated later to produce an informative map detailing various features and environmental concerns picked up throughout the entire stretch of the Dorpspruit.This along with a detailed report of the walk will be used to input into the sustainable use and management of the Dorpspruit River.
Each day started at 08:30 or 09:00 am with a driver dropping us off at the exact spot where we’d ended the day before. During the walk itself an array of information collecting tools were utilized, from individual note taking, camera/video recording to using Mini-SASS score sheets and IHI (Integrity of Habitat Index) score sheets.
From confluence to source, river left and right of the Dorpspruit comprises of vast alien vegetation and few indigenous and pristine stretches. There are few un-impacted areas consisting of natural vegetation along the river. From the confluence the river moves from an upper foothill environment being moderately steep and consisting of a cobble-bed or mixed bedrock-cobble bed channel, to an environment with a very steep gradient dominated by bedrock and boulders with cobble and coarse gravels in the river channel.
Surrounding land use within the river is predominantly for residential and industrial purposes as the river itself flows through mostly the urban jungle of Pietermaritzburg. In the upper reaches of the Dorpspruit this gradually changes as agricultural activities start to take centre stage. Both of these land uses have heavy impacts on the river due to the numerous activities that the river is exposed to. What was clearly apparent from this walk is that the majority of the river is choked with alien invasives. The river constantly showed signs of nutrification as the river waters were very murky whilst passing through urban areas. Large patches of bramble and poplar plantations were observed within the final stretches of the Dorpspruit – nearing its source.
Many developments neighbouring the Dorpspruit do not respect/obey the 32 metres buffer, either by constructing buildings, erecting fences/walls, by planting of timber, informal settlements, gardens, lawns and uncontrolled invasive plants. From our observations the river water was found to have great excess nutrients from various types of urban/industrial effluent. This was clearly evident from the change in water colour of the river itself. Some stretches of the river were found to be algae green robbing the waters of the Dorpspruit of oxygen. However, it is not all doom and gloom for the Dorpspruit. By implementing the correct evasive/control action, large stretches of the Dorpspruit can be healed.
The team of six conducted Mini-SASS activities at various nodes of the Dorpspruit to determine the health of the river and give us a detailed picture of the Dorpspruit’s ecological standing. These informal assessments (Mini-SASS) allow one to have a hands-on experience to find out what the current state of the river is (a very timeous process). With such assessments one is able to monitor water pollution levels at any point of the river using the classification/scoring of certain aquatic invertebrates found in the waters.
Mini-sass activities were conducted at various points along the Dorpspruit. We were able to conduct numerous assessments due to the fact that the majority of the river is naturally shallow with us being able to walk in-stream for a great part of the walk. This, in most cases made accessibility very simple and with the Dorpspruit being fairly rocky we had no lack of rapids and riffles which are essential environments for conducting Mini-SASS. Average readings that we received from all our assessments indicated that the river was in a fair condition (moderately modified). Readings varied from a poor to fair condition.
An Integrity of Habitat Index (IHI) assessment closely looks at the habitat characteristics of a river both from an in-stream and riparian zone perspective. The assessment as a whole tasked us as individuals to look and assess the overall composition of the river looking at the ecological state of the dorpspruit.these assessments were done at separate 200m stretches of the river. In stream and riparian zone aspects of the river were assessed separately and each were graded accordingly. After the walk itself, all individuals involved in the walk are to come together and conduct a workshop, collectively assessing the ecological state of the Dorpspruit using the IHI criteria.
The walk ended on Thursday the 17th of July at what we felt was the source, about a kilometre from World’s View road.