Stormwater Management Introduction

Question 1

True or false; nearly all greenfield and brownfield sites require some form of stormwater management.

Answer 1

True - almost all developments require a stormwater management scheme.

Question 2

What is the definition of stormwater management?

Answer 2

The design and implementation of a system to control the quantity and quality of stormwater run off.

Question 3

Stormwater Management is often referred to as SUDS (Sustainable Drainage Systems); true or false?

Answer 3

True - it’s also known as Surface Water Management too.

Question 4

What are the two common types of stormwater management systems used in the UK?

Answer 4

Soakaways and Attenuation Systems

Question 5

Climate change is the sole reason why more frequent flooding takes place; true or false?

Answer 5

False - development of urban areas paves over permeable land and decreases the natural ability of land to soak up water.

Question 6

How does Stormwater Management reduce the risk of flood events?

Answer 6

Run off is stored in one location and gradually released into the ground rather than being allowed to enter the watercourse uncontrolled.

Question 7

Why would stormwater run off not soak into the ground?

Answer 7

Because of impermeable surfaces or poor ground conditions (such as heavy clay).

Question 8

Where does stormwater come from?

Answer 8

Prolonged rainfall and storms as well as when snow/ice melts.

Question 9

If you’re building a supermarket you won’t need a stormwater management system; true or false?

Answer 9

False - a large roof and car park will make much of the land impermeable and require a stormwater management system.

Question 10

Which of JDP’s Stormwater Management products can be adopted?

Answer 10

Crates
Large Diameter HDPE
GRP Tanks
Oversized Concrete & Plastic Pipes

Question 11

You can assume all products are adoptable; true or false?

Answer 11

False - the adopting authority must approve the products

Question 12

Name the 6 main additional products for Stormwater Management systems.

Answer 12

Geotextiles & Membranes

Interceptors

Concrete Manhole Rings & Axedo

Flow Control Valves

Silt Traps & Catch Pits

Channel Drainage

Question 13

What are the two types of separators JDP can provide?

Answer 13

Bypass Separators

Full Retention Separators

Question 14

Maintaning or improving the funtion of the solution - whilst reducing the total cost - is known as what?

Answer 14

Value Engineering

Question 15

Stormwater Management is central to JDP’s strategy; true or false?

Answer 15

TRUE

Question 16

Impermeable membranes and protection fleece are used together; true or false?

Answer 16

True - the membrane retains the water. The fleece protects the membrance from damage.

Question 17

SUDS is an abbreviation of what?

Answer 17

Sustainable Drainage Systems

Question 18

Large Diameter HDPE and Crates may be refered to as ‘tanks’; true or false?

Answer 18

True - attenuation structure could be refered to as a ‘tank’

Question 19

Which is the most common type of flow control device?

Answer 19

Vortex Flow Control devices

Question 20

Can Large diameter HDPE be adopted?

Answer 20

Yes - large diameter HDPE can be adopted.

Question 21

Major infrastructure projects usually have 20m3 tanks or below; true or false?

Answer 21

False - highways and large schemes have tanks with storage up to 1000m3

Question 22

What type of developments will usually need 100m3 storage or below?

Answer 22

Commercial developments

Housing developments

Question 23

What are the four main customer types who work with Stormwater Management systems?

Answer 23

Groundworkers

House Builders

Civil Engineers

Drainage Contractors

Question 24

What is the purpose of a soakaway?

Answer 24

To store stormwater that is gradually soaked into surrounding ground.

Question 25

What is the purpose of attenuation?

Answer 25

To store stormwater and release into a watercourse at a pre-agreed discharge rate.

Question 26

If a soakaway system is to be used what test takes place to find the discharge level?

Answer 26

Percolation test.

Question 27

Name 2 of the most common discharge points for an attenuation system.

Answer 27

Open Watercourse

Existing Sewer

Question 28

What percentage of runoff is created by having impervious / impermeable cover such as roofs and roads?

Answer 28

55%

Question 29

What are the two main factors for determining which stormwater management system is used?

Answer 29

Ground Conditions

Location of Project

Question 30

JDP Technical Support can only assist with schemes that have a storage size larger than 500m3; true or false?

Answer 30

False - Technical Support can provide assistance for any size scheme.

Question 31

JDP’s Technical Support service charges 5% of the project cost as a fee for support; true or false?

Answer 31

False - JDP’s Technical Support team services are free to customers.

Question 32

Impermeable membranes feature in which stormwater management system? Why are they used?

Answer 32

Attenuation systems - used to prevent water escaping from the structure.

Question 33

Why is a non-woven protection fleece used in attenuation systems?

Answer 33

To protect the the impermeable membrane from damage.

Question 34

On a soakaway system a silt trap is not used; true or false?

Answer 34

False - a silt trap is still used before the crate structure to filter debris.

Question 35

JDP’s Technical Support can provide solutions from multiple manufacturers; what are the main benefits of this?

Answer 35

Technical Support can offer the right solution for the project based on location and ground condition - potentially lowering project costs.

Question 36

Impermeable surfaces create 5 ½ times more runoff than natural ground cover; true or false?

Answer 36

True - 55% runoff compared to 10%.