DROP Level 3 Rainwater Harvesting Calculation (Desktop Feasibility)
If you're considering rainwater harvesting on a commercial scale or trying to achieve water neutrality a Level 3 Rainwater Harvesting Calculation may be suitable. Our level 2 analysis is available for free by clicking this link.
For large or complex schemes where significant economic benefits might be realised or where there is a temporal variation in demand it is suggested that continuous rainfall time series (or simulation modelling) should be used to address this variability in order to optimise the design in accordance with BS EN 16941-1:2018.
DROP is an application of the storage equation on a continuous daily rainfall time recorded in eight geographic areas (SW England and West, SE England, Central England, NW England and Wales, NE England, S. Scotland, N. Scotland, E. Scotland). Calculated storage and overflow are displayed as exceedance curves.
The output is a one page pdf document containing the :
- optimised storage requirements
- reduction in mains water usage
- proportion of time the tank overflows
- budget cost benefit analysis (commercial only)
- Overflow Analysis
- CO2 saved
What we require:
- Site Location/ Site plans/Elevations/Drainage Plans showing WC locations
- Roof type (slate, concrete tiles etc)
- Usable contributing drainage roof area to the rainwater tank
- Type of usage for which rainwater will be used
- Existing water usage data if available
- Proposed demand from rainwater tank e.g 1m3/day
- Typical occupancy if relevant to proposed rainwater usage
- Whether a location for a loft/header tank tank is available
- Roof Type (tile/metal profiled etc.)
Assumptions
- Filter efficiency is 90%
- Yield based on roof type (Table 1 BS 8515:2009+A1:2013)
The pdf will be delivered to the email address you have registered with.
If you are combining attenuation with rainwater harvesting please contact us first.
Allow 10 working days for the output to be delivered from supply of information requested above.
If your query is related to an existing order please email in with your order number in the subject line. If you have a new residential enquiry please consult the online guides before calling as they may answer your question.
The delivery information page is divided into 1. Specific and 2. General delivery information below.
1. Specific Delivery Information relating to product lines- Small items dispatched daily with RM24 ~85% arriving next day
- Large items (UK made) typically 5 - 15 working days (Parcelforce/APC etc)
- 1,000 litre compact underground rainwater tank
- 250 litre Prestige large Plant Pot style planter Grey
- SAR40-TOP2 Wastewater Lifting station
- Madison 185 Litre rain barrel
- Hydraloop
- Green Roof sedum tray - pre planted option
- Madison 185 Litre rain barrel - Millstone
We're a Manchester based company and ship to the UK at our standard rates. Please get in touch requesting the delivery surcharge value if you are based in the Highlands or a UK island.
We no longer support ordering from the EU and Northern Ireland through the website. We can support ad hoc orders with limited liability.
Our design and Prestige range is available in the Netherlands, Ireland, Belgium, France, Germany, through our distributors.
Stock items will be dispatched on the day of order, if ordered before 1pm.
Letters are sent 1st class.
Parcels <2kg are shipped with Royal Mail 24 Tracked with the following target delivery times.
Guaranteed delivery can be arranged by advance agreement. This agreement is back to back with the courier and we will not be liable for any delays as per our terms.
A loss/replacement can only be pursued in line with the target delivery times of the courier or once the courier accept loss.
Bulky items (and pallet deliveries) are dispatched within 2-15 working days. We will request a contact number if this has not been provided at checkout.
Some items are made to order (bespoke) and details are given on the listing for dispatch times. If for any reason we anticipate a delay on our normal dispatch time we will contact you to let you know.
Occasionally there are delays. We shall not be liable for any direct or indirect losses, costs, damages or expenses incurred by you or any other person for any delays in delivery.
Missed deliveries where attempted delivery has been made usually result in re-deliveries the following day. The customer is responsible for organising re deliveries by contacting the courier direct.
Parcels/deliveries can only be "left out" if the delivering company allows that option. Parcelforce, for example, do not allow a parcel to be "left out".
We are an environment centric business and as such we try to minimise our waste. Our packaging is usually recycled and/or recyclable and we make efficient use of packaging to minimise wastage.
Covid delivery updates between 12.3.20 and 11.1.21 21 have been archived here.