WHERE HAS ALL THE WATER GONE?

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“It never rains in Southern California”! In seven days starting in mid-December 2010, the Los Angeles area received over seven inches of persistent rainfall, averaging over one inch per day. On a typical 7,500 square foot city lot, that is almost 4,400 cubic feet of water, or roughly 33,000 gallons. Where does that water go? Unless a property is well-drained, too much of that rain-water ends up under the house undermining foundations, seeping through slabs, and flooding crawl-spaces. This in turn contributes to settling of floors and foundations, buckling of wood floors, musty odors, mold and mildew.

When rain hits the ground, it either runs off or soaks in. Soil can only absorb water at a limited rate. In very sandy soil water moves straight down at a high rate. In anything other than very sandy soil, water moves laterally as well as vertically through the soil. Water in saturated soil next to the house is moving towards the dry soil under the house. When the water hits the footings of the house, it percolates down, under the footing, and then comes back up under the house to the same level as the water outside the house.

Uncontrolled roof-water is the most common source of water under the house. Gutters are usually the easiest way to capture and control roof-water. Gutters redirect roof-water into downspouts. But if the downspouts empty the water next to the house, the concentration of water is magnified at the place of discharge and can actually make the threat more severe. Rain-water from gutters needs to be taken away from the house to a safe discharge. This can be done with a paved surface that does not allow the water to flow back towards the house, or with an underground pipe that takes the water to the street or other safe discharge location.

Water that lands on the yard next to the house needs to flow away from the house. If the yard is flat or sloping towards the house, the water will pond and saturate the soil, ending up under the house. To avoid this, the ground should slope away from the house at a rate of ½ inch per foot or more and go into a drainage system or onto yard with slope of 1/4 inch to the foot beyond the first 10 feet. Any water collected in a drainage system needs to be taken to an approved storm-water system, most commonly the street.

Water that soaks into the ground in the yard and neighborhood above the house can work its way downhill towards the house, eventually working its way under the house. When we have prolonged, continuous rains, such as the seven days in December of 2010, soils become saturated and lateral underground movement increases. This is when some water intrusion problems become more visible. The longer the period of continuous or frequent cycles of rain persists, the more likely subterranean water problems are likely to become apparent. These types of problems can sometimes be alleviated by improving the uphill surface drainage on the property, but often a French, or subterranean, drain system with perforated pipe and gravel is the most effective treatment.

Though it does not rain frequently in Southern California, when it does, the rains can create severe problems, especially where provisions for drainage are minimal or poor. In those cases, the answer to the question, “Where does all the water go?” is often, “In or under the house!”

Regular Yard Drain Cleaning And Maintenance

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If you have a yard drainage system that you depend on to carry water away from your house and property when it rains, you should make sure to maintain it. If you don't, you might not find out until it's too late that it's not working the way it's supposed to. Regular maintenance of a yard drainage system, including cleaning of catch basins, swales and drain inlets and snaking or hydro-jetting of drain lines, is very important. Debris, roots and dirt can eventually build up and choke your drainage system. We often find systems that haven't been maintained for years have pipes packed solid with dirt:






We recommend an annual drainage maintenance call before the rainy season. Hammer Company provides this service, which typically includes checking and cleaning all catch basins and drain inlets, snaking or high pressure water jetting of underground drain pipes, and testing to see if water introduced into these drains runs out the discharge as it's supposed to (usually to a curb drain at the street,) and if it does so in a timely fashion. If minor cleaning and drain clearing doesn't get the water draining as it should, we can investigate and/or replace portions of the drain line.

Additionally, sump pits should be regularly cleaned, at least annually, and sump pumps tested to make sure they will activate when you need them to.

A yearly maintenance call can save you a yard flooding incident or even water from getting into your house or garage. The water is much harder to deal with once that's already happened!

Storm Water Mitigation System Inspections

If you live in the City of Santa Monica and have an urban mitigation pit as part of your drainage system, you may be required to have an annual inspection for Best Management Practice (BMP) on an infiltration pit or depression basin. You might receive a letter from the City of Santa Monica that starts out like this:

"Your property has participated in the City's Urban Runoff Management Program through the installation of a Best Management Practice (BMP) device, such as an Infiltration Pit or Depression Basin, when construction work was performed in the recent past (since 1999.) The City's Urban Runoff Pollution Ordinance, SMMC 7.10, requires that most major development or construction projects install a physical structure within the property, in the landscape or under the garage (some commercial and multi-family buildings) or driveway, to capture precipitation from roofs and other hardscapes for infiltration or treatment and release to the street. This program seeks to keep small background levels of pollution found in urban runoff off City streets, where it flows untreated into the Santa Monica Bay, and can cause beach postings and closures. This program also seeks to harvest a local water resource and infiltrate it into the ground for groundwater recharge and potential future extraction as a local water supply, reducing dependence on expensive imported water or to harvest into a cistern for reuse."

What does this mean for you, the property owner? You may be required to have an annual visual inspection of your urban runoff mitigation or infiltration system, and turn in paperwork stating that you have done so. We can perform this visual inspection for you.


Our minimum Stormwater Mitigation System Inspection typically consists of:

1. Visual inspection of first-story gutters and any gutters visible from stair-case accessible upper story rooms or stair-case accessible flat roof. This inspection does not include putting our men on a slopping roof, or on a ladder extending beyond one story. If you want gutters inspected that exceed these limitations, we recommend contacting a gutter-cleaning company with appropriate workers compensation coverage for that work.

2. Where practical and accessible as provided in #1 above, hose-water test first-story downspouts to see if water flows through the spouts.

3. Visual inspection of deck and yard drain-inlets so see if they are clear of debris and silt.




4. Hose-water test of main drain from an accessible clean-out or drain inlet to see if water backs up. Basic inspection is based on one line only. If additional lines are needed and authorized, there would be additional cost. Note: A hose produces only a fraction of the flow of a rain-storm and does not detect less than full obstruction. For a more complete evaluation of drain condition the line would need to be snaked and/or videoed, neither of which is provided for in this basic inspection.




5. Visual inspection and quick clearing of pre-pit screen box (up to 12 X 12 by 18 inches deep. Larger or multiple filtration boxes will require additional time and cost.

6. Hose test of drain pipe from pre-pit screen box to pit. This is to verify that water does not back up into the pre-pit screen box.

7. Open inspection-hole cover at the pit and check for standing water. If the inspection hole access is buried, additional costs will be necessary to locate and access the inspection hole.

8. If overflow pipe inlet is accessible, hose-water test overflow pipe to see that it is clear to the street. Other wise run a tape or snake from the street outlet to see if the pipe is open from the street to the pit. Note: A hose produces only a fraction of the flow of a rain-storm and does not detect less than full obstruction. For a more complete evaluation of drain condition the line would need to be snaked and/or videoed, neither of which is provided for in this basic inspection.

Many single family residences, and some larger properties that are regularly inspected will fall within the minimum fee. The minimum fee covers 2 men for up to one hour. If problems are observed, we will report such problems together with recommendations, and where appropriate, estimate costs for treatment. If in-line filters are used on the site, the minimum charge does not include cleaning or replacing the filters. Depending on site conditions, we usually recommend eliminating multiple in-line filters and small pre-pit filter boxes and replacing them with one, large, serviceable filter and inlet box at the pit itself. Our minimum inspection does not include the cleaning of gutters or drains.

Some infiltration pits have been built with overflow drain pipes at the pit higher than inlet pipes. We do not recommend or approve such designs. Usually, we cannot determine whether or not the overflow pipe is lower than the inlet pipe without conducting a separate video inspection, which we do not include in our basic inspection, and is not typically required by the city.

Please take note that infiltration systems retain water on the site that normally would be conducted off the site. This can introduce unintended consequences of unpredicted proportions, especially where there are below-grade structural components such as basements and footings. Also, this type of inspection typically cannot tell us anything about the condition and capacity of the pit itself, or how effectively it is allowing infiltration into the soil. Also, because of the typical pit design, we cannot tell whether the pit will allow overflow water loads to actually reach the overflow pipe without backing up into the main system. In order to confirm this we would need to run a very large amount of water into the pit and observe its performance, which is not included in this minimal inspection. In inspecting the stormwater mitigation system we only report readily observable conditions and problems. We do not thereby approve or certify the overall suitability of the system for the site.

To order an inspection, please call and schedule it with our dispatcher. Please provide us with any information you may have regarding the location of the pit (or pits), the location of the inspection hole (not all pits have inspection holes), and access to a copy of any available plans or drawings used for construction of the pit. If you wish to have your drain lines snaked, hydro-jetted, or repaired during the process of the inspection, or filters and/or basins cleaned at the time of inspection, or sump-pits cleaned and pumps tested, please indicate so when you order the inspection and increase the budget to provide for additional work that will be charged on a time and material basis with the 2-man crew being billed at $170 per hour. The amount of time it takes to clean drain components can vary widely. Therefore we recommend a minimum of a $500 budget for combined visual inspection and minimal cleaning. If more extensive cleaning and or repair is needed, labor and incidental material for a full day on a job-site typically cost between $1,800 and $2,300. If you anticipate extensive problems with a large or old drain system, you may want to consider authorizing a budget of up to one day at a time for the most efficient use of the crew.

Sprinkler Efficiency Under Mandatory Restrictions In The Los Angeles Area

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High water bills have prompted homeowners to investigate the efficiency of the sprinkler system for their properties. Many homeowners trying to water within regulations or recommended watering levels are observing extensive plant stress, particularly in turf. When turf areas are under-watered they typically exhibit blotchy patterns of stress. Our experience is that such variability becomes manifest as water application is reduced due to multiple factors such as; uneven distribution of water over the area, varying soil conditions, shifting patterns of shade and sun, seasonal fluctuations in evaporation, and variations in weather. Other factors that produce similar symptoms include disease, animal urine, over- or uneven application of fertilizer.

Focusing only on water-related factors, it is necessary to water any given section of plant material to the highest need in that section in order to achieve relative uniformity of appearance. Except for very large areas such as football fields, golf courses, and large floral parks where spacing of sprinkler heads is not dictated by tight or curvilinear plant borders anything approaching optimum sprinkler application efficiency is not possible. Under the best conditions, the efficiency of application of water by sprinklers (or even drip) only approaches 70%. Typical urban and residential properties will be much lower, even with the best design and equipment. Statewide standards for irrigation efficiency have been developed based on ideal spacing of sprinkler heads in the absence of obstructions, imprecise borders, etc.. As a result, adoption of water conservation regulations has an overall fundamental bias against the typical homeowner from the beginning. This bias pushes the homeowner towards watering to the minimum for the least needy portion of a section of plant material, leaving the higher need areas stressed. With water regulations based on this type of standard, most homeowners will be penalized for higher than theoretically "necessary" watering levels to avoid stressing plant material.

However, there is an even more confining element to California state-mandated water regulations and standards -- that is choice of plant material. Even if a sprinkler system was at peak efficiency, much or most of plant material in residential gardens may exhibit severe stress under mandated water regulations or recommendations because most regulations are not based on existing plant materials or homeowner choices of desirable plant material, but on what someone else has decided homeowners should choose. Some people in power positions in the state and some communities have decided that the appropriate flora for Southern California is desert, and that anybody who chooses non-desert plant materials should be penalized with fines or higher water rates if they try to water accordingly. Tiered watering rates make sense when they relate to the increased costs of obtaining more water and are essentially tied to market forces. However, some communities are imposing much higher rates and penalties which are not tied to market forces but political ideology that impose an artificial uniformity of life-style. Under these definitions, a term such as "Excessive Use Charge" does not necessarily denote that a homeowner is being penalized for reckless use of water, but rather that the homeowner is being penalized for attempting to maintain plant material that does not conform with desert ideology.

This is important to understand because with typical home landscaping you can never be good enough to satisfy the standards of the regulatory agencies unless you severely stress or kill the plants. Even then it is important to realize that most water regulations are based on an annual average and do not allow for variations throughout the seasons. For instance, regulations in the City of Los Angeles only allow for watering levels at about 1/2 the summer level for the average landscape throughout the year, including the summer. Thus at this time of year, homeowners attempting to comply strictly with City of Los Angeles restrictions are experiencing severe dieback in their gardens.

With the above limitations in mind, the objective for sprinkler maintenance for existing plant material is to try to eliminate gross imbalance where practical. This will not eliminate plant stress, but will tend to even out the stress. Another measure that may provide practical benefits is to change the sprinkler controllers to ones that either automatically adjust watering times by season, or ones that have a weather sensor that adjusts watering times for daily changes in weather. Here's the rub, however. Under regulatory guidelines, watering times in the summer are about half the normal recommended level to maintain healthy plant material, especially for turf. Improving efficiency will improve, but not remedy that sort of problem. Also, smart controllers are typically designed to meet normal water needs of plants. Smart controllers will always call for watering beyond severe regulatory levels, and therefore have little impact throughout at least half of the year.

New Los Angeles Water Restrictions

Yesterday the LA City Council approved an updated version of the watering restrictions. Under the previous regulations watering was only allowed on Mondays and Thursdays. Under the new revisions you can water up to three times a week, and which days you may water are determined by whether your street number ends in an odd or even number.

Odd numbered addresses can water on Mondays, Wednesdays and Fridays while even numbers can water on Tuesdays, Thursdays and Sundays. If your address ends in a fraction, the number that precedes it determines your watering days.

Additionally, the amount you can water with traditional spray or bubbler heads has been reduced from 10 minutes per watering day per station to 8 minutes. Rotor heads and water-saving rotary style heads may be run for 15 minutes at a time, and twice per watering day per station, a definite increase from before, and an amount much more likely to keep your yard alive. It appears that those are the major changes. The new revisions will go into effect until 5 days after Mayor Villaraigosa signs them into law, probably by Labor Day.


The DWP's fact sheet can be found here.

SANTA MONICA SPRINKLER OVERSPRAY AND RUNOFF CITATIONS

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Santa Monica homeowners are becoming aware that if they are cited for overspray or runoff from their sprinklers, their options are limited and more costly than they expect. In the past, runoff problems were usually related to a broken head or pipe, or a misdirected sprinkler head. Today, the definition of acceptable runoff has changed from “less than lots” to “none.” This is a standard that is virtually impossible to meet with any spray or rotor system, except for very large properties with only large planting spaces. There are no residential properties that large in Santa Monica. Thus every homeowner with a sprinkler system in Santa Monica is liable to being cited any time of the day or night, any day of the week. Carefully designed and installed sprinkler systems are being cited right along side the most carelessly and poorly conceived systems.

Usually there are several modifications that can be made to sprinkler systems to reduce overspray and runoff. These might include (1) adjusting heads, (2) repositioning heads, (3) reducing the radius-of-throw of heads, (4) adding heads, (5) changing heads to higher pop-ups, (6) replacing old heads, (7) adding regulators to reduce pressure (and fogging), (8) adding check-valves to prevent drainage of heads. Some combination of these changes can often lead to dramatic reductions in runoff. Usually, the more extensive the modifications, the more runoff can be reduced. However, no amount of decreased overspray or runoff can assure that citations will not be issued.

The City of Santa Monica encourages what are called “low-precipitation” sprinklers to reduce runoff. However, low-precipitation sprinklers have severe limitations in small spaces because their length of throw is much longer than the usual spray sprinklers. In addition, the shorter low-precipitation sprinklers are less precise than the longer ones or spray heads, further frustrating adaptations for existing sprinkler systems.

While modifications of existing sprinkler systems can be as little as a minimum service call or some minor adjustments costing between $95 and $150, most modifications to address overspray and runoff on an average residence in Santa Monica will cost much more. For instance, changing all the nozzles on the parkway and the front yard might cost $500 or $600. But that alone would probably leave dry areas and still significant runoff and overspray. Often some heads need to be repositioned and modified throughout the parkway and front yard, typically costing between $1,500 and $3,500.

These costs are based on conditions a few years ago. Today the city imposes new restrictions and requirements on much of the work of modifying sprinklers that significantly increase the costs. The most significant is that of a reinterpreting an old city ordinance on parkway work to require an encroachment permit for installation or modification of sprinklers in the parkway. Our family has been in the sprinkler business in Santa Monica since 1926. It is only in the past five years that the city has been interpreting the municipal code in such a way that working on sprinklers in the parkway requires an encroachment permit. This means that work cannot be performed until a permit is obtained, usually meaning a delay of 1 to 4 days, a $179 fee, and the expenditure of significant time to pull the permit and return on another day to do the work. This requirement alone typically adds $370 to the cost of work that requires any digging in the parkway.

Another significant change over the past few years is that the public works department now requires that sections of sidewalk be cut, removed, and replaced to accommodate running a supply pipe under the sidewalk to the parkway. This work, process, and permit fees add about $1,000 to the cost of accessing the parkway with a new pipe. Previously it was acceptable to bore under the walk with a tight hole to install new pipe, a very quick and inexpensive procedure not requiring a permit.

There are a number of other regulations that impact the cost of system modifications, such as requiring a 24 inch buffer zone with no sprinklers next to walks, curbs and driveways. At the very least, this requires revising the entire sprinkler system in the affected sections. With recent city restrictions, permit fees and requirements, etc. most of the typical modifications to reduce runoff and overspray on existing sprinkler systems have increased in cost from $150 to $450 on the low end, and from $3,600 to $4,000 on the high end. None of this work can be guaranteed to preclude citations for overspray or runoff.

The most effective approach to minimizing overspray and runoff is to replace portions, or all, of a sprinkler section with drip. Drip conversion is not cheap. It is very labor intensive. Whereas redoing an existing parkway with spray heads might cost $1,200, redoing that same parkway with drip would cost $3,400. Similarly, instead of redoing the front lawn sprinklers at a cost of $2,700, redoing the lawn in drip might cost $5,700. The total cost of converting the parkway to drip and doing a 24 inch perimeter in drip for the front yard would be around $9,000 in this example. In my view that is not the end of the higher cost of drip. A good installation of underground piping for a spray system can be expected to last 50 years or more. I think drip will have a relatively brief life, especially if damaged in such a way as to allow dirt into the line. Though spray systems require periodic maintenance of sprinkler heads, I think drip will require periodic replacement, probably within ten years.

So it is a difficult choice for homeowners. On one hand there is drip with much higher installation and replacement costs, less flexibility in plant installation and replacement, but low or zero overspray and runoff, or on the other hand is spray with higher overspray and runoff, but lower cost and more flexibility. In the past, achieving full, even coverage of all plant material was the primary objective in sprinkler installations. Now full, even coverage must be sacrificed if overspray is to be reduced, or drip must be utilized.