STRI agronomy manager, Paul Woodham, considers the actions golf courses can take to minimise the damage from severe weather and return the course to a playable condition.
Flooding in the UK
We have unfortunately become all too familiar with the media reporting on flooding during the recent months. Seemingly biblical rain events falling upon already saturated ground have affected many areas with Sheffield, Lincolnshire and the Midlands being amongst areas where the UK media have reported on the misery caused to homeowners, retail and farming.
Much is being said about the issues associated with the possible impact of climate change. Indeed, many of my articles of the past few years have centred on the problems which come with managing golf courses during periods of weather extremes such as intense heat, drought, prolonged frost and of course wet conditions.
Turf will in time recover with the correct maintenance and repair although there may be interruption to play and with the playing quality, however the damage sustained is nothing compared to seeing ones homes, possessions, crops and livestock consumed by floodwater.
The challenge for golf
The challenge for golf courses is as always to ‘manage the agronomic conditions which will ensure you are in the best place possible to deal with environmental pressure’. This invariably means dealing with water and the best courses all exhibit ‘good drainage’.
This is fundamentally a cornerstone for course management whether offered through naturally good draining soils and good maintenance or supported by effective drainage schemes and clever course designs. Sadly, not all courses are geographically or agronomically blessed with free draining soils or have the designs which will alleviate problems. Your course may be open to flooding beyond your control even with redesign as the power of floodwater and storms can be immense.
There are occasions when the golf course is designated as a flood alleviation area. This may be forced upon you with compulsory reclamation of the course and new land offered for development in return.
This was the scenario for a scheme in Birmingham which led to the creation of three new holes in return for accommodating an Environment Agency flood embankment project allowing the River Tame to flood the course to protect downstream inhabitants from a one in 100 year flood event; the likes of which last occurred during 2010 when 10,000 homes were flooded.
Flood defences and alleviation schemes may be on a much smaller scale than EA designed flood embankment projects. Indeed, in house projects can include simple reshaping in areas of the course commonly flooded by surface run-off water entering bunkers, or elevating tees and greens for example. Perhaps medium scale in the latter example and a situation where a skilled contractor and correctly designed specifications need to be included.
Course maintenance and flood mitigation measures are sometimes left forgotten. Watercourses may need maintenance; elements of management that the government has been recently criticised for scaling back expenditure for large scale maintenance. Small scale dredging and clearing can be done on-site but of course checking for the impact on the ecology and responsibly executing the work. The objective is to ensure high volumes of fast flowing water can exit the course and lower the water table, if achievable.
What happens when the course succumbs to flooding?
Litter and debris are the immediate concerns. There may be sewer debris contamination from blown drains so ensure there is a risk assessment in place to tackle the clean up operation. Visible debris may include aggregates such as stone washed from paths or adjacent roads.
This clean-up is harder to deal with but any buried stone left in the turf base could be damaging to mowing equipment and golf clubs taking a divot. Such levels of serious contamination are rare and can normally be dealt with by painstaking shovelling and brushing.
Irrigation control boxes are unfortunately ready-made water traps. It is important to clean out any soils which have migrated into the boxes and have buried the valves and electrics such as wires and solenoids. Check the function of the electrics at an early stage, not just in the spring commissioning works scheduled right when you need the system operating.
What about the damage beyond the visible carnage of litter and loss of grass cover where the flooding has suffocated the turf? The physical contamination left from flooding may include silt deposits. These can be damaging to the longer-term surface drainage of turf and bunkers.
Silt and soil fines contamination of bunker sand is more visible than deposits laying within the turf base. Damage will be sustained to the physical characteristics and playability of sand. The sand may need to be stripped out of the bunker and replaced in the worst cases of flooding.
Many courses are investing in redesigning and renewing the construction profiles of bunkers to include a permeable membrane which will protect the bunker from contamination of the sand from below, thereby improving drainage and overall maintenance and playability.
To date, I am not aware of problems where silt deposits have entered the bunker sand and migrated into the membrane to block or slow the drainage, but it would be wise to remove any of the soil contamination debris from the sand surface or replace the sand before this has a chance to damage the membrane.
Silt deposits can have the same damaging impact if the soil fines create a layer which interrupts the uniformity of the upper profile soil texture and structure. Fortunately, most deposits will be compatible with the native soils inherently forming low-lying heavier commonly soils exposed to flooding.
The deposits can be problematic if capping drainage profiles or previously sand dressed areas. Some form of removal (scarification, coring) or penetration (aeration) may need to be applied in advance of redressing to dilute the contamination.
Flood damage can adjust the soil chemistry, often not visible until there is evidence of turf decline in areas previously affected by saltwater (coastal storms or high tide flooding). Extraction of soil cores from affected areas sometimes exhibit anaerobic conditions forming due to the soil structure degrading.
Salinity levels may have increased to surpass a threshold whereby longer-term damage to plant health and soil structure could occur. Research suggests that the species of plant retained within the affected areas have a tolerance of 3-6mS/cm whilst ESP (exchangeable sodium percentage) breaching from 5-10% may exhibit sand particle migration with a threshold ≥15% causing adverse effects.
Those affected by coastal flooding may need to check the physical and chemical status of soils before implementing aeration and soil amendments such as Gypsum, or investing in overseeding only to see less salt-tolerant grass species fail.
The last point to consider is how to apply recovery aeration, top dressing and managing play back on to damaged areas. This is perhaps as simple as ‘be patient’ and ‘manage your expectations’. There is little point in aerating saturated soils even if water is perching in the upper profile.
The added weight of aeration equipment, or allowing soft ground to be pulverised by play, could be counterproductive. Apply corrective aeration when the soils are receptive to treatment. Sand dressing may need to be applied to help dilute silt contaminated turf base conditions but the same applies; wait until conditions are conducive to achieving the desired result. Correct the damage and then consider what measures, such as design changes, can be applied to prevent repeat damage.
If you have any questions or comments on this article, contact Paul Woodham on Twitter.
For advice on dealing with flooding at your golf course, contact STRI on +44 (0) 1274 565131 or email: firstname.lastname@example.org.