If you live in an urban area, you may have experienced urban floods commonly characterized by flooded streets and low-lying urban areas. These floods develop quickly due to faster flow times over impervious surfaces. This results in loss and damage to vital infrastructure and livelihoods while the secondary effects of pollution linger long after the flood event. With weather events expected to get more extreme, the impacts will only get worse. The stormwater infrastructure in many urban areas, at present, is insufficient to deal with current and future rainfall events. The unmanaged stormwater is akin to cracks in a wall that are bound to get worse if not addressed, with the ability to paralyze activities in urban areas. A case in point is the 2021 flooding that resulted from the remnants of Hurricane Ida in New York, where up to 3 inches of rain an hour resulted in devastating flash floods in the city.
Authorities in New York have however been learning from previous flooding events and are implementing measures to control flooding and pollution in New York. This is best exemplified in Gowanus. Gowanus is a neighborhood in Brooklyn, New York that was recently rezoned and is set to see a lot of new development in the coming years. To protect the neighborhood from loss and damage, the neighborhood will adopt green infrastructure to control flooding and pollution. There is also a new unified stormwater rule requiring large lots to retain rainwater with technical guidelines provided in a stormwater manual.
We are offering a smart, sustainable urban flood solution through the use of smart, affordable, coupled water height, water velocity, and street imaging sensors. The coupled sensors monitor water flow on selected street sections and relay early warning information where pre-determined street flows values are detected.
b) The service: Locating the smart, street water flow sensors and green infrastructure installations
In addition to the product, we are offering a service that will;
The service solution is based on the use of Geographical Information System (GIS) technology. GIS will be applied to determine the contribution of upslope areas to the flooding experienced within the low-lying urban areas. The service solution works in the following way;
a) Mapping of flood-prone areas. Places at greater risk such as subway stations and basement apartments will be mapped.
b) Next, identify the stormwater infrastructure network that would drain through the mapped flood-prone locations.
c) Sub-divide the contributing area into sub-catchments using existing drainage networks. I.e. identify different sub-catchments according to the junctions of the drainage network.
https://experience.arcgis.com/experience/7c260f80c5d44d948d45051d7a2d6d77/page/Page-1/?views=View-2. (Markers added for illustration purposes)
d) Evaluate the characteristics (geomorphology) of these sub-catchments. For example, different shapes, sizes, and drainage densities would result in different rates of flow.
e) In addition to the characteristics, we would also employ video analytics to determine the velocity of water along the streets. We will use existing footage from Closed Circuit Television (CCTV) cameras of the flooding events to detect and track objects carried by the runoff.
f) With this information, we would identify the source and volumes of stormwater runoff. We will thus be well informed on where to place our smart sensors as on the choice, capacity, and location of green stormwater infrastructure to install.
There are benefits to such an approach where sensors and green infrastructure are distributed over an entire catchment rather than concentrated in low-lying areas. The benefits include;
The current solution is intended for urban authorities who are responsible for the Environmental Protection and Management of Urban areas. We have considered sustainability in the use of affordable sensors as well as through distributed smaller green stormwater installations.
We offer the following services in relation to our solution;
a) Development of low-cost sensors with the capability to measure street water elevation and velocity as well as cameras to provide visual records of urban flood events.
b) Spatial analysis to determine suitable locations for sensors and green installations. Deliverables of the analysis include a detailed report on the runoff paths and sub-catchment characteristics. We will also include recommendations on the street sections to install smart low-cost sensors as well as suitable locations for green infrastructure installations that will help to manage the stormwater runoff.
We are a start-up consultancy from Kenya currently comprised of four members. We would like to connect and engage with you on smart sustainable urban flood solutions.