Stormwater Management Introduction Flashcards
True or false; nearly all greenfield and brownfield sites require some form of stormwater management.
True - almost all developments require a stormwater management scheme.
What is the definition of stormwater management?
The design and implementation of a system to control the quantity and quality of stormwater run off.
Stormwater Management is often referred to as SUDS (Sustainable Drainage Systems); true or false?
True - it’s also known as Surface Water Management too.
What are the two common types of stormwater management systems used in the UK?
Soakaways and Attenuation Systems
Climate change is the sole reason why more frequent flooding takes place; true or false?
False - development of urban areas paves over permeable land and decreases the natural ability of land to soak up water.
How does Stormwater Management reduce the risk of flood events?
Run off is stored in one location and gradually released into the ground rather than being allowed to enter the watercourse uncontrolled.
Why would stormwater run off not soak into the ground?
Because of impermeable surfaces or poor ground conditions (such as heavy clay).
Where does stormwater come from?
Prolonged rainfall and storms as well as when snow/ice melts.
If you’re building a supermarket you won’t need a stormwater management system; true or false?
False - a large roof and car park will make much of the land impermeable and require a stormwater management system.
Which of JDP’s Stormwater Management products can be adopted?
Crates
Large Diameter HDPE
GRP Tanks
Oversized Concrete & Plastic Pipes
You can assume all products are adoptable; true or false?
False - the adopting authority must approve the products
Name the 6 main additional products for Stormwater Management systems.
Geotextiles & Membranes
Interceptors
Concrete Manhole Rings & Axedo
Flow Control Valves
Silt Traps & Catch Pits
Channel Drainage
What are the two types of separators JDP can provide?
Bypass Separators
Full Retention Separators
Maintaning or improving the funtion of the solution - whilst reducing the total cost - is known as what?
Value Engineering
Stormwater Management is central to JDP’s strategy; true or false?
TRUE
Impermeable membranes and protection fleece are used together; true or false?
True - the membrane retains the water. The fleece protects the membrance from damage.
SUDS is an abbreviation of what?
Sustainable Drainage Systems
Large Diameter HDPE and Crates may be refered to as ‘tanks’; true or false?
True - attenuation structure could be refered to as a ‘tank’
Which is the most common type of flow control device?
Vortex Flow Control devices
Can Large diameter HDPE be adopted?
Yes - large diameter HDPE can be adopted.
Major infrastructure projects usually have 20m3 tanks or below; true or false?
False - highways and large schemes have tanks with storage up to 1000m3
What type of developments will usually need 100m3 storage or below?
Commercial developments
Housing developments
What are the four main customer types who work with Stormwater Management systems?
Groundworkers
House Builders
Civil Engineers
Drainage Contractors
What is the purpose of a soakaway?
To store stormwater that is gradually soaked into surrounding ground.
What is the purpose of attenuation?
To store stormwater and release into a watercourse at a pre-agreed discharge rate.
If a soakaway system is to be used what test takes place to find the discharge level?
Percolation test.
Name 2 of the most common discharge points for an attenuation system.
Open Watercourse
Existing Sewer
What percentage of runoff is created by having impervious / impermeable cover such as roofs and roads?
55%
What are the two main factors for determining which stormwater management system is used?
Ground Conditions
Location of Project
JDP Technical Support can only assist with schemes that have a storage size larger than 500m3; true or false?
False - Technical Support can provide assistance for any size scheme.
JDP’s Technical Support service charges 5% of the project cost as a fee for support; true or false?
False - JDP’s Technical Support team services are free to customers.
Impermeable membranes feature in which stormwater management system? Why are they used?
Attenuation systems - used to prevent water escaping from the structure.
Why is a non-woven protection fleece used in attenuation systems?
To protect the the impermeable membrane from damage.
On a soakaway system a silt trap is not used; true or false?
False - a silt trap is still used before the crate structure to filter debris.
JDP’s Technical Support can provide solutions from multiple manufacturers; what are the main benefits of this?
Technical Support can offer the right solution for the project based on location and ground condition - potentially lowering project costs.
Impermeable surfaces create 5 ½ times more runoff than natural ground cover; true or false?
True - 55% runoff compared to 10%.
