Case Study: Effective Management of Storm Water in Urban Spaces

Sustainable Urban Economic Development Programme (SUED) Effective Management of Storm Water in Urban Spaces- A Case Study on Isiolo Municipality Challenge The Kenyan Government has undergone significant changes since its independence in 1963, key among them the shift from a central government to a devolved one after the promulgation of a progressive constitution in 2010. Devolution provides people an opportunity to participate in decision-making on how resources within counties are managed to advance the counties priorities. As such counties have recently been pressured by the populace to have demonstrable outputs that showcase their economic development. This has resulted in many counties promoting urban development geared towards meeting the need of their growing urban population. However, as the counties put in place infrastructure, they have inadvertently encroached on water catchment areas resulting in poor urban water management. Furthermore, managers of these new urban centres in the counties have faced the challenge to better manage the amenities they provide while giving priority to how the new infrastructure impacts the environment and responds to climate change.

The country has seen an increase in flooding within its urban areas that has resulted in serious damage to businesses and infrastructure, highlighting the importance of effective urban storm water drainage. The practice within the counties has been to implement mono-functional drainage concepts that only address one drainage need within the urban centre. This approach often results in flooding due to the increase in water surface runoff and decreased volume flow. This has been further exacerbated by developments along riparian land, poor sanitation practices that include poor disposal practices that have led to garbage and floating litters increasing the sedimentation of the water system.

Counties are yet to put in place effective measures that help them foresee how to best manage stormwater within their urban centers. There is a need to provide technical support to help them plan, design and develop responsive and implementable storm water management plans. This plan should incorporate features that increase resilience to future climatic shocks. The need for a responsive stormwater management system is critical in Kenya where 80% of its land mass is classified as Arid and Semi-Arid and can significantly benefit from the proper management of their storm water to harvest and store their flood water for future use during dry seasons.

In Isiolo Municipality, there has been an increase in population from around 46,500 in 2009 to 80,500 in 2019 - almost doubling in a decade. As such, demand for urban services has increased.

While this demand is justifiable, the municipality and wider county have additional pressure to

scale up their urban development due to the transitional nature of the town and the future national level economic development projects that are earmarked for Isiolo such as the Lamu Port-South Sudan-Ethiopia Transport Corridor (LAPPSET). This means Isiolo’s urban expansion has and continues to have threats to its capability to be adequately climate resilient. This is due to its arid nature that disposes it to long periods without rain and short periods of intense rainfall that leads to flooding and soil degradation which reduces agricultural productivity and impacts the sustainability of its urban settlements.

Further, its urban center remains susceptible to extreme weather events with multiple flooding experienced in the rainy season due to its topography. The urban center is located on a low-lying floodplain characterised by steep gradients which make it vulnerable to rapid flow of stormwater from the upstream catchment areas of neighbouring counties. This has resulted in significant property damage and population displacement with an estimated 1,320 households displaced between 2009 and 2019 while the 2015 floods are estimated to have resulted in KES 800 million of property damage.1 2 The urban area’s soil also has a high clay content and limited vegetation due to its semi-arid nature. These combine to significantly reduce water retention and increase surface water runoff which is worsened by the poorly maintained storm water drainage systems.

The county government also struggles to fund new storm water drainage systems due to the pressures of supporting its large vulnerable population, who frequently need humanitarian assistance.

Intervention As a response to this, the UK Government through its Sustainable Urban Economic Development Programme (SUED) is working with 123 municipalities, including Isiolo, to improve the resilience of their urban environments and drive sustainable economic development. Embracing climate change adaptation by developing climate resilient infrastructure will ensure urban centres face minimal disruption from adverse weather and safeguard municipalities’ economic gains. The programme is doing so by working closely with the county and municipal leadership to develop climate smart Urban Economic Plans4 (UEPs). The UEPs outline how municipalities can build their infrastructure to support the capacity of its people as well as absorb direct and indirect impacts of climate change.

Within the UEP development process, the programme embeds a strong urban climate resilience lens helping the municipalities see how they can embrace climate change adaptation, determine what mitigation actions need to be taken and see how best to reduce the risk that adverse climate events cause. The programme does so in the following ways: a) Strong Stakeholder Engagement: The programme works with its supported municipalities to learn directly from the stakeholders what their economic priorities are and further what is the largest deterrent to their economic growth. By understanding what the populations are most susceptible to with regards to external shocks including climate change. The 1

County Government of Isiolo. (2018). Isiolo County Integrated Development Plan, CIDP 2018-2022 Japan International Cooperation Agency (JICA). (2014). Isiolo River Basin Flood Management Plan 3 Lake Region Economic Bloc- Kisii and Bungoma, North Rift Economic Bloc – Eldoret and Iten, Frontier Counties Development Council- Mandera and Isiolo, Mt. Kenya and Aberdares Region Economic Bloc- Kathwana and Kerugoya/Kutus, South Eastern Economic Bloc- Kitui and Wote, Jumuiya Ya Kaunti Za Pwani- Malindi and Lamu 4 Urban Economic Plans are advisory documents that complement the County Integrated Development Plans to help provide a focused economic strategy that highlights which priority value chain and critical infrastructure should be prioritised to advance local economic development. Read more about UEP here: https://www.suedkenya.org/urban-economic-plans 2

programme has been able to work with municipalities to make significant decisions in planning, utilisation of land within their territories and what climate-resilient infrastructure projects need to be prioritised. b) In-Depth Assessments and Analysis: In the case of Isiolo, through its UEP development process, the programme has incorporated a multi-faceted approach in its assessment of a municipality’s demographics, economy, infrastructure, environment, and climatic conditions. In its assessment of Isiolo municipality, SUED was able to see how rainwater continually drains into the surrounding hillsides and converges in the urban centre causing flooding of up to 500mm resulting in damage to livelihoods, property and causing a lot of displacements which is a financial burden to the municipality/county. The urban centre with its limited green infrastructure and lack of surface water management in place continues to be at risk of flooding. c) Development of a Responsive Framework: SUED works closely with the municipal and county leadership to develop local solutions. This involves an iterative process that helps the municipality and county key decision makers see how to find solutions that are beyond their current challenges. This is critical as climate remains unpredictable and there is need to inculcate a culture of looking at existing issues and see how a locality’s climate change may evolve either in its increase or decrease of an existing hazard such as flooding to help integrate future possibilities in current planning. Working with Isiolo’s county and municipal leadership, SUED worked on a development framework that looked at the urban centers’ typology to determine the support need to improve the municipality’s capability to respond to urban growth whilst building climate resilience. d) Informed Visioning: In its finalisation of the UEP, the programme together with the county and municipal leadership set the municipality vision and identify their key economic priorities. For Isiolo it was key to ensure that its economic priorities include a holistic approach to storm water management. The incorporation of a local solution to protect both its populace and infrastructure from flooding in its urban center was necessary due to the magnitude of flooding. As such, the programme was able to propose a local Sustainable Urban Drainage System (SuDs) in the Central Busines District (CBD).

This final stage enabled the municipality to visualise how the SuDs would intercept overland overflows and be directed through a bio-park into a natural reedbed system. As a result, the municipality identified its vision- “Develop Isiolo as a centre of Excellence and a Major Economic Hub in Kenya with Resilient and Inclusive Growth through the Responsible Use of its Natural Resources.” While the proposal for the SuDs within the UEP is critical in Isiolo’s storm water management, it cannot stand alone to adequately support the municipality in its stormwater management. It is therefore imperative for the municipality to explore how they can increase the capacity of their river (River Marire) to enable safe water conveyance through the urban center.

Result With a development framework in place that is based on resilient urban development, Isiolo municipality now has an effective urban economic plan that clearly articulates how it can utilise proper river flow management and build SuDs to become flood resistant. Further it outlines how the municipality can develop robust water infrastructure to strategically harvest and store water.

To help them bring this plan to fruition, the programme supported the municipality to commence an investment attraction process that would better prioritise and refine its stormwater management through its SuDs project. Key among its support is to assist the municipality assess

the practicality, sustainability, and impact potential of the SuDs to ensure it promoted a sustainable climate-resilient infrastructure.

The programme did so by supporting the municipality to carry out a prefeasibility study of its SuDs project. The prefeasibility study used a technical, financial, socio-economic, and environmental assessment criterion. The study entailed secondary research, in-depth discussions with the municipal and county leadership as well as key stakeholders, site visits and analysis to help better assess the SuDs project feasibility to enable SUED work with the municipality to recommend the necessary steps to implement it.

As SUED supported the municipality to carry out the pre-feasibility study on the SuDs project, it identified the key barrier to its implementation. While there were workable drainage systems designed, they were yet to be constructed due to county and municipal budget constraints. In addition, the municipality lacked a strong stakeholder coordination approach that would enable it to partner with the private sector to address this. By utilising the prefeasibility study to identify the barriers to the successful implementation of the SuDs project, SUED was able to assist the municipality develop potential implementation steps that would actualise the project.

First, the municipality would need to prioritise the construction of drainage channels around its airport and feeder roads within the municipality as well as rehabilitate drainage channels. By doing so the channels will redirect stormwater away from residential, commercial, and academic spaces to the River Marire. Second, River Marire needs to be expanded and individuals living on its riparian land resettled. This will enable it to safely channel stormwater at peak discharge. Third, the development of a semi-natural bio-park to enable the utilisation of 25% of the stormwater flowing into the municipality. By doing so, the captured water would be utilised within the park to create a green space for the urban center’s population as well as generate income for the municipality by charging access fees to the park. And fourth, the construction of four5 check dams in catchment areas in the neighbouring Meru County to reduce the volume and velocity of floodwater flowing to Isiolo Municipality.

In sequencing these steps, the municipality will be able to enhance its climate resilience and help create adaptation opportunities such as the storage of water for future use during dry seasons.

Furthermore, the SuDs project will help the municipality enhance its adaptation against adverse weather events and resultant socio-economic damage and losses. The SUDs project will improve the municipality’s economic resilience as it will not have to cater for costs associated with damage caused by floods to commercial and industrial premises and residential properties.

The SuDs project is one that ensures Isiolo’s climate resilience is demonstrable as it is reflective of the municipality’s adaptive planning that incorporates future integration of climate extreme events. In addition, it is robust with a multi-faceted approach in the way it uses various components to address geo-specific issues within the municipality. Additionally, its capability to incorporate the complementarity of different aspects of the project to support each other if one aspect fails to mitigate the management of stormwater demonstrates its effectiveness. The SuDs project is flexible to adopt a sequential approach in addressing its stormwater management. This will be crucial in enabling the municipality to respond to the changing conditions (i.e. developmental and climatic). However, there is need to ensure that there is community buy in for the SuDs project, the municipality will need to have in-depth consultations and diverse 5

Check dam is a wall built across a waterway to reduce the velocity of runoff water.

engagements with the community especially with individuals whose businesses or residents are on the riparian land.

By implementing the SuDs project, Isiolo will be able to appropriately mitigate flooding within its urban area through the implementation of a multi-faceted drainage system that has been designed to provide the fastest and most effective transport of stormwater runoff out of the catchments into River Marire. This collaboration between SUED, the county, the municipality, and other donor agencies to drive investments into the proposed urban system will ensure the safety of the public and minimise the environmental impact of urban stormwater, making the municipality climate resilient.