Irrigation Ponds - Sizing, Volumes help...

[Ryan Crago]

A bit of a technical question for all in the business (or otherwise):

I'm looking for a resource for designing irrigation systems for new golf courses, specifically on how to size irrigation ponds, and if possible, the integration of stormwater and/or greywater (wastewater) into the irrigation system.  

Obviously the sizing is a function of irrigation volume requirements, rainfall and other local geographic data, all of which i have.  i'm looking for a backup source to confirm my findings, and potentially enhance the design and functionality.

if anyone can help, or point me in the right direction, it would be much appreciated!

rc.

[Peter Galea]

If the pond is visible or in play, make it as large a surface area as you can. This will reduce drawdown during use and save you from unsightly banks or "bathtub ring" on the "gunnite". If evaporation is a concern, disregard or try to balance out the above.
Keep the pump station filtration flush a good distance from the intake.
Speaking of intakes, spend the extra money and get a stainless steel cage for it. It's cheaper than replacement and all that goes along with that (re-fabrication and a diver or two). Build a 'maintenance pad" below it to keep it out of the silt. Consider this in sizing because the water below the top of the intake is unusable.
While it is essential to have steep sides to keep weed growth down, it's even more important to have a "safety ledge". This will reduce capacity, so factor that in when sizing. Insist on a safety ledge.
Ideally, you would like to be able to refill the pond during the eight to ten hours you irrigate. This will all depend on use, capacity and supply.
After rereading your post, I guess these are answers to questions you didn't ask.
Contact me offline for more info if you want.

[Jim Johnson]

Ryan,

I don't know if this helps, but in his book "Golf Course Architecture", Michael Hurdzan writes that in the U.S. Midwest, it is generally agreed that fairways need about one inch of water per week to keep turfgrasses healthy. Greens and tees need about one and a half inches of water per week.

He cites an example of 50 acres of fairways and "near roughs", equaling 50 acre-inches/week x 27,000 gallons/acre-inch, totalling 1,350,000 gallons of water/week for fairways & near roughs. For greens and tees, he figures 10 acres x 1.5 inches of water/week, x 27,000 gallons/acre-inch, totalling 405,000 gallons of water/week, for a combined total of 1,755,000 gallons of water/week for the entire golf course.

As Hurdzan notes, a golf course located in an arid region may require three times this amount of water.

JJ

[Tom_Doak]

Most grasses require about an inch of water per week, if you are trying to keep them green.  But you also have to figure in the evapotranspiration loss in hot months -- this is why desert courses require so much more, NOT because the grasses themselves need it.

[Forrest Richardson]

Ryan... I am leery of passing too much advice because it is an interrelated set of issues. You really need a golf course architect to work with you. Even a qualified irrigation designer is not able to answer all of the issues — agronomic, playability, etc.  

If drawdown is an issue (such as mentioned when a pond is visible) then you need to focus on edge treatment and volume — which usually means depth. Surface area is only one part of the equation.

[Larry_Rodgers]

Ryan,

[Larry_Rodgers]

OOPS happy mouse again.
First: What is the reliability & quality of the source?
 a good source would allow for a smaller reservoir

Second: What is the frequency of application?
 If your desire is hard, fast uniform conditions, you will need a larger reservoir to apply great amounts each evening for deep soil replentishment.

Third: How much "mud flat/freeboard" do you want to see in the morning?
  A larger surface reservoir will drawdown slower than a smaller surface reservoir.

Fourth: What part of the world is the golf course located?
  As noted before there will be many additional agronomic considerations before the actual size cane be determined. Lake Mead is a good size to start with, but there are many great courses with no reservoir at all.

[Ryan Crago]

gentlemen (and ladies),

many thanks for taking the time to answer my questions.  I've been out of town for a few days (playing golf of all things), and away from GCA.

I suppose it is prudent for me to give more information on the site i am working with, and the project itself...

The project itself is my masters of landscape architecture thesis.  I will save you the details of my thesis arguement, but the reason I started the thread was to get a better idea of how to plan, size and design an irrigation pond system, integrated with a stormwater management program.  I have researched the topic extensively, and have found bits and pieces of information on irrigation/sizing requirements, and a lot of preaching of "one should do this or that", however very little explicit information on how it is executed in the real world.

The information you've given already is great, but maybe i can squeeze a bit more out of everyone here if I provide more site info:

Location:  Surrey, BC, Canada - characterized by mild wet winters, and warm, dry summers.  

Site Size: approximately 280 acres, gently rolling, with average grade on the site 6.5% falling from NE to SW.

Veg. Cover: 80% Young deciduous forest, with some mature conifers 20% old field habitat and agriculture fields.

Soils: less than ideal.  low to med surficial permeability. marine and glaciomarine stony and stoneless silt loam, with some sand and silt.

Annual Precip:  1400 mm/year

Estimated Pre-Dev't water balance (round figures):
total precip over site = 1,900,000 cubic metres
estimated evap:       =  866,000
Total run off:           =  200,000
Infiltration               =  833,000

Estimated Post Dev't (based on current concept)
Total Precip:           = 1,900,000
estimated evap:      =  858,000
estimated runoff      =  340,000
Infiltration              =  702,000

My Estimated Irrigation requirment (based on current concept):  
180,000 gallons/day during June-Sept
25,000,000 gallons/year total

Water Source:  Many servicable wells exist on site, providing from 3-10 gpm.  Wells no longer used as a source of drinking water.  Little surface water on site - a significant wetland that must be protected, and 4 small seasonal streams.

Turf Selection: Undecided.  Assuming a colonial bent? which is well adapted to the regional climate.


Clearly the goal here is to capture and reuse (for irrigation) as much of the precipitation as possible.  My question now goes beyond the sizing and water requirements, into HOW to integrate the systems, WHERE to integrate the systems, and WHAT does it look like?  

As mentioned, there seems to be very little literature for me to pull from, so any direction towards resources, or any professional (or amateur!) advice is VERY appreciated.

I also hope no one minds my candidness regarding the project.  I do appreciate your help!

ryan.

[Jeff_Brauer]

At 3-10GPM, I wonder if the wells are worth the electricity to run them.  You need to investigate deeper acquifers, since those old farm wells were never intended to supply the water needs of a golf course.  Many times its either the depth of the well or the size of the well casing that limits water so severely.

Since streams are seasonal, and dry when you need the water most, I figure you need total supply of 125-150GPM, and more would be nice.  Do authorities and water law allow capture for your use?

I wouldn't count on runoff at all, but to capture it, you need your irrigation lake in the lowest part of the property where it will capture most.  If there are other lakes, you should connect them via pipe or waterfall so overflow water from those lakes goes down to the main irrigation lake.  (I did this in Indonesia one time, using miles of large pipe)  Pumps from lake to lake are an option, but do cost money to run, while gravity doesn't, and need someone reasonably intelligent to run them, whereas gravity works for free.

Actually, if the space requires and allows, you could have several lakes at the same elevation and connected below water with 18-24" pipes, and they would all function as one.  Otherwise, any non-irrigation should be very small to minimize evaporation.  The irrigation lake should be at least one 1.25 acre, with 2-3 preferred to keep draw down each night to less than six inches.  The irrigation lake should also be at least 8-10 foot deep for a safety margin.

With going back and forth between metric and English, I can't easily convert all of your numbers, but the 180K GPD sounds about right for a norther climate.  I presume you will only actively water tees, greens and fairways, which should total less than 90 acres or so.  

[Bruce Katona]

I can't do the metric conversions very quickly either, but 30,000,000 gallons per month during dry weather is about what we use during the summer to stay somewhat green.

 Perhaps split the lakes in half - one on each nine for both aesthetics and to minimize the amount of area you need to push water axcross until its gets to where it needs to in the pipes.

We try for 10 feet of depth with a safety ledge 3-4' off the top of proposed surface elevation so someone doesn't fall in and drown.

As someone who has lived this, propose to drill additional wells to get to the 150-200 gpm range for each, in diffeent locations on site (perferably located close to the proposed lakes). A 200 gpm well  ets you 4.3 million gallons per month (pumping 12 hours, watering 12 hours).  This pumping rate equates to 144,000 gallons/ day  (excluding evaporation).  You will be putting out 180,000 gallons/ day to irrigate so you will need to run the pumps to keep the lake level up.

Permitting this from the authorites may be difficult....there are very detailed studies required to get the ok to pull out this much water from the ground.

If you need real technical help, I'll hook you up with our hydrogeoligt who can get you enough info for you thesis.

[Forrest Richardson]

Ryan — At first pass it sounds to me that you have a fluctuating water supply (run-off) and a great differential. At least that seems what you need to plan for.

So, my approach might be to begin with devising a collection system for the water through the site. (The best way to manage water across a site is with water. By this, I mean a linear string of wetlands or lagoons will allow you to drain the site in close proximity and take the water to a downstream holding pond (reservoir).

So, to recap: If you were to create a long string of wetlands (shallow ponds) it would serve to collect water, store water, filter water...and eventually feed a pond which could be much smaller, and also cleaner. All of the silts and bad gunk collected would (long term there may be adjacent development that dumps rooftop and parking and road water to the course...?) be filtered and eventually ponded.

Your irrigation source would be the pond at the low end. It would be just large enough to hold what you need for irrigation.

To further make the system whole, you would likely want to design mechanical gates in the wetlands string of ponds which could, in a drought condition, allow water to escape the shallow wetlands and make its way to the golf irrigation pond.

See? The effect is a large holding capacity without having to always have it full. The wetlands would appear fine when full...and also as natural native areas when empty, or near empty.

I may be (wisely) countered on this approach from some of my more learned colleagues. But, you still owe me a beer.