Background
Castle Moat House is a beautiful Grade II listed city villa, nestling just beneath the historic Lincoln Castle walls. Lincoln Castle is a major medieval castle constructed during the late 11th century by William the Conqueror on the site of a pre-existing Roman fortress, and is one of only two castles in the whole country to feature two mottes. Lincoln Castle remained in use as a prison and court into modern times and is one of the best-preserved castles in England – with one of the buildings within the complex still in use as Lincoln Crown Court to this day. Indeed, displayed within the castle is one of only four surviving exemplars of the Magna Carta of 1215. The castle is a nationally recognised archaeological site, and is open to the public most days of the week, with walks along the top of its impressive, high walls providing stunning views of the castle complex, cathedral, the city, and miles of rolling countryside.
The Irrigation Project
Access Irrigation were responsible for the design, supply, and installation of the complete Castle Moat House irrigation system watering the rear garden lawn of Castle Moat House. This was an extremely unique garden as backed directly on to the ancient caste walls themselves – with a mound rising steeply at the end of the garden on the left, where the lawn met the colossal castle walls.
The system was fully automated, using a highly reliable Hunter X2 irrigation controller. A ‘WAND’ Wi-Fi module was included to allow the controller to be operated remotely from any computer, Android, or iOS device and to automatically adjust irrigation schedules based on local weather data, enabling substantial savings in water use.
To comply with the Water Regulations, the system included a pre-assembled break tank and pump. The tank included a Type AB air gap to prevent backflow into the public mains and was supplied with a float valve inlet, to prevent the tank from overfilling by closing the tank inlet when the water level raises the float valve too high. The pressurised water supply to the system was provided by a compact Lowara BG series pump featuring a stainless-steel body and motor shaft for long life. A Lowara Genyo pump starter was included to operate when there is a demand for water and to provide dry running protection – ensuring that the pump will not be damaged. For neatness and ease of installation, the pump and tank are supplied pre-assembled, both fitted securely to a solid base. The controller, and pump and tank were located within a shed at the right-hand corner of the garden nearest the house, being powered by mains electric.
Hunter PGV solenoid valves were used to split the system into 6 separate zones (one solenoid valve per zone), allowing each zone to operate at a separate time and duration according to separate watering requirements, thereby enabling efficient watering for each zone. The 6 solenoid valves were housed in 2 underground valve boxes located just before the start of the lawn – one valve box located on the left side, the other on the right. These valve boxes were connected to the controller via multi-core signal cable and connected to the pump & tank via MDPE supply pipe. Both the signal cable and supply pipe were housed in underground trenches – being buried 300mm below the surface, to ensure protection from overhead foot traffic and frost.
Each solenoid valve is opened and closed in sequence by the controller. When the first valve opens, the pump detects a drop in pressure (due to pressure release from the open valve) and will begin to operate to boost the pressure back up again. This will cause water to flow through the first (now open) solenoid valve to water the first zone. The controller closes the first valve, and immediately opens the next valve in the sequence. Once the last valve has closed, the water flow will cease, pressure will build again, and the pump will stop operating.
Most of the lawn was watered using unobtrusive Hunter PGJ Rotator pop up sprinklers, which sit at just below the mowing level when not in use, ensuring that the system is completely invisible when not operating. PGJ sprinklers are renowned for their superb build quality, and feature a ‘top-down’ design that allows all servicing to be carried out from above – preventing the lawn from being damaged. PGJ sprinklers also include built-in drain check valves to prevent water wastage and puddling. For the steep slope (reaching the castle walls) at the far left of the lawn, a Hunter I20 Ultra popup sprinkler was used, positioned at the highest point at the end of the slope, facing back towards the garden. Due to the steep elevation involved, this sprinkler was fitted with the addition of a Hunter HCV adjustable drain check valve to prevent water from puddling at the base of the sprinkler to protect the castle walls behind, and to prevent water from collecting at the bottom of the slope, thus ensuring that the whole lawn was watered evenly. This sprinkler was also given its own zone, to allow complete control over its watering duration to ensure that the correct amount of water was applied. The PGJ sprinklers forming the other 5 zones were arranged in separate straight rows, running from the valve boxes down to the end of the lawn – with each zone including between 2 to 4 sprinklers depending upon the position of the zone. The sprinklers within the zones running down the middle of the lawn were set to water full circle, with those within the zones running down the left and right edges of the lawn set to water half circle (facing towards the lawn) to prevent overspray occurring on non-lawned areas.
The Installation
Our experienced engineers were responsible for the installation, testing and commissioning of the complete system. This was carried out in phases according to actual site conditions and the program of works. Once the installation was complete, we provided the client with full instructions regarding the operation of the system, enabling them to competently manage and maintain the system by utilising its full potential.
The Result
The Castle Moat House irrigation system we supplied has resulted in a lush, green lawn that is now a pleasure to behold against the epic backdrop of the castle walls. We are delighted with the result and are proud to play our part in helping gardens within historic areas flourish.
