By Danielle Alvarez, Biologist, RCDSMM
Editor’s note: Post updated to reflect salient comments by Marti Witter, Fire Ecologist at the Santa Monica Mountains National Recreation Area – Thanks Marti! ~Tanessa Hartwig, Environmental Services Coordinator, RCDSMM, Feb 12, 2019
I don’t think anyone needs convincing that conditions are getting more extreme for us here in southern California. Summer temperatures keep on hitting record highs, we’re constantly waiting to see if we are going to get any rain during the winters, and the fire season in between is getting more intense and dangerous. The past fire season was devastating for the Santa Monica Mountains and all its residents, both human and animal. While we all hope a fire event won’t happen for a long time, there is no guarantee there won’t be yet another fire next year. But preparing for the future, whether it be another wildfire or the after effects of the last fire, is what all residents who call the beautiful Santa Monicas their home can do right now.
Extinguishing the wildfire itself brought most people at least some relief. Sadly, some 1500 structures were destroyed, and many homeowners are now in the process of rebuilding. We can now assess the damage and set a plan in place to begin to bring life back to a state of normalcy. However, after a devastating wildfire, rain – which is something we all desperately want down here in drought-stricken southern California – poses the next imminent threat. Vegetation that would have held soils in place has turned to ash, and the soil can quickly be mobilized by a rain event. The dangers of mudslides in a post-fire area are well known by long time homeowners who have dealt with previous fires. If the Woolsey fire was your first major fire in the area, then you’re probably learning quickly that the fire itself is just the beginning. If you’re not sure what steps to take for post-fire preparedness with your property, we’ve compiled a list of things to know – and DO – to ready yourself for post-fire rain and potential mudslides.
Rain is on the way! What should you do?
First and foremost, FOLLOW EVACUATION ORDERS:
As hard as it might be to leave your home, especially if you were evacuated during the fire, please follow evacuation orders. If you are close to a burned slope or stream course, your home may be at risk of mud or debris flows. Flooding will occur more rapidly and with less rain than would cause rising waters under normal (pre-fire) circumstances. No amount of surface treatment will stop mud and debris flows. Put you and your family’s safety first and evacuate. Not sure where to find up to date information on evacuations or road closures? The Los Angeles County website has an Emergency page that has information on emergency preparedness and even a sign-up for emergency alerts, as does Ventura County. To learn more about mudflow protection or request engineering advice, visit the LA County Public Works website. In Ventura County, Ventura County Recovers has comprehensive information about recovery efforts for both the Woolsey and Hill fires.
PREPARING PRIOR TO RAINFALL:
There are, however, measures that you can take to protect your home if it has been identified as being at risk from mudslide damage. Filling and placing sandbags one to two feet high around the perimeter of your home before a predicted rain can help protect it from shallow mud debris flows. If you need to use sandbags don’t forget to place the bags with the folded top in the upstream/uphill direction, facing the flow of water, so they don’t open when water runs by them. Doors and windows will still be points of vulnerability, so boarding up and waterproofing them with plastic sheets will help protect against water and debris flow. Need help finding sandbags in your area? Enter your address here and LA County Public Works will tell you the nearest fire station where you can get free sandbags. Ventura County Fire Departments also provide bags and sand to fill them during the rainy season.
Preparing for mudslides is not an individual effort. You probably have at least one neighbor and you all have the same interest in this matter: protecting your property and homes. Because of your proximity, you should work together to decide how to place your sandbag walls in a way that directs debris flow away from your homes, pools, or other structures and does not direct these flows to any downstream neighbor’s property. Work with each other to develop a “Culvert Watch” system. Most of the ditches, drains, culverts, and other structures that are in place are undersized to handle runoff conditions in an extreme post-fire landscape. It is super important to diligently check on and clear out all drainages to keep them from clogging and creating serious flooding and mudflow hazards. The tortoise beats the hare here; continual maintenance and debris removal is vital. Only work during safe runoff conditions and NEVER work during actual flows. Note that we are NOT saying to clear debris from the slopes themselves- more on this below.
After the Rains
So now that the rains and potential for mudslides have passed……what’s next? Depending on your landscape – native wildlands or garden or something in-between – you can watch the cycle of natural recovery or start to plan for your new landscape. Post-fire replanting is the perfect way to get your property ready and protected the next time a fire happens.
Unsure where to start? The Natural Resource Conservation Service (NRCS) and your local Resource Conservation District – that’s us! The Resource Conservation District of the Santa Monica Mountains (RCD or RCDSMM)/ NRCS – or your local department of public works – is a great starting point to assess your property so you can understand changes to expect from your post-fire landscape and how to best meet your recovery goals. CalFire and local fire district officials, US Forest Service, and National Park Service are also important resources to tap regarding fire hazard reduction and ensuring your replanting plans do the most to make your property fire safe.
Drainage Dos and Don’ts
Assess and map out all drainage, irrigation, and utility pipes on your property (including pipe drains, roof gutter drain outlets, culverts). Plastic drains and irrigation lines could have melted or been destroyed in the fire-fighting effort. Before proceeding with drainage repairs or improvements, consult with NRCS/RCD, an engineering geologist, or Certified Erosion Control Professional (CERP) for planning information on controlling drainage around your property. This can help prevent application of the wrong drainage control design — which may potentially cause more harm than good, and at the very least might be a waste of money. Existing, even burned, vegetative cover will reduce and slow surface runoff and improve your soil’s infiltration capacity. Don’t cover damaged slopes with plastic sheeting. While you may think it will prevent slope failure or protect bare soil, it will increase runoff and erosion and can kill the root systems of native plants trying to re-establish themselves. Straw wattles, mulching and plantings are examples of sediment control measures that can help prevent eroded and displaced soil from entering roadside ditches and waterways- but again, without professional design and installation (not found in the average landscape company), these wattles and other surface treatments might simply become part of a debris flow.
Pruning Dos and Don’ts
You will probably want to clear the burned and dead debris off your property as soon as the fire is gone and that is understandable. However, when you’re clearing out damaged vegetation, don’t be too quick to give every fire-kissed plant the axe. Many damaged or scorched native plants will re-sprout, including trees that were not completely burned! Looks can be deceiving. Oak trees that were severely burned can come back, so start off with pruning before removing the entire tree. Also, depending on the species, you may need to obtain a permit prior to cutting down any trees on your property. LA County Dept of Regional Planning or Ventura County Planning Division is the place to start for permitting, unless you live in an incorporated city – in which case your city’s Department of Planning will have permitting information. Sometimes, doing nothing is the best option! Burned plants and even surface debris protect the soil from the direct hit of raindrops, which can displace soil particles as much as 5 feet from the impact point. Allowing natural recovery and re-establishment of native plant cover may be the best route. Again, NRCS/RCDSMM or a CERP are great resources to tap into to find out what your property needs. Don’t rely on your neighbor’s plan because every property is different, and the damage done by a fire will be unique to each property.
Re-Planting Dos and Don’ts
In areas where you do not have native vegetation, this is the perfect opportunity to rethink your landscape and re-plant your property to be more fire resistant, sustainable, and wildlife friendly.
Going straight to the “Erosion Control Seed Mix” is a big no-no when gearing up to replant a fire-damaged property. More often than not, they contain non-native grasses and legumes or California natives that are not indigenous to southern California and therefore not intended for our wild-lands or fire-recovery. In fact, they might include seed that will result in particularly “flashy” fuels by the next fire season. Re-seeding with locally sourced grasses and plants should be executed selectively, because they may discourage local natives from reestablishing on their own. If you decide to replant, make sure to choose drought tolerant, fire retardant natives when re-planting. Using seed or planting stock that is native to the area will help you bolster your landscape’s success and re-sprouting ability should another fire occur and provide much-needed habitat for local wildlife (many of which also lost their “homes” in the fire!). Many of our local shrubs, with their deep roots adapted to our drought-impacted climate, are also excellent slope stabilizers. These include: manzanitas, buckwheats (Eriogonum spp.), California lilacs (Ceanothus spp.), laurel sumac, and lemonade berry. These plants also exhibit fire-resistant characteristics such as low fuel volume, little excess dead wood, and a high moisture content. Need some additonal ideas for drought tolerant or fire-resistant shrubs or trees local to the Santa Monica Mountains? Here are just a few!
Shrubs: Laurel Sumac (Malosma laurina), Prickly-Pear Cactus (Opuntia littoralis), Lemonade Berry (Rhus integrifolia), Coffee Berry (Frangula californica), Toyon (Heteromeles arbutifolia), Cleveland Sage (Salvia clevelandii), Big Berry Manzanita (Arctostaphylos glauca)
Trees: Coast Live Oak (Quercus agrifolia), Black Oak (Quercus kelloggii), Madrone (Arbutus menziesii), California Buckeye (Aesculus californica), California Wax Myrtle (Morella californica), California Bay Laurel (Umbellularia californica), Western Redbud (Cercis occidentalis)
Trees/Shrubs for riparian or irrigated areas: Western Sycamore (Platanus racemosa), Big Leaf Maple (Acer macrophyllum), Blue Elderberry (upland as well) (Sambucus nigra var. caerulea), Thimbleberry (Rubus parviflorus), California Hazelnut (Corylus cornuta var. californica), Creek Dogwood (Cornus sericea ssp. occidentalis), Red or White Alder (Alnus rubra, A. rhombifolia)
Perennial Forbs: CA Rush Grass (Juncus spp.), Yarrow (Achillea spp.), California Poppy (Eschscholzia californica), Penstemon (Penstemon spp.), Blue-Eyed Grass (Sisyrinchium bellum), California Buttercup (Ranunculus californicus)
Grasses/Groundcovers: California Oat Grass Danthonia californica), Foothill Needle Grass (Stipa lepida), California Fescue (Festuca californica), Alum Root* (Heuchera spp.), Yerba Buena*(Clinopodium (Satureja) douglasii), Wild Strawberry* (Fragaria californica)
*grows near perennial water
This is by no means an exhaustive list, but it’s a place to start. For more information, visit the Los Angeles/Santa Monica Mountains Chapter of the California Native Plant Society website and check out their list of recommended native plants for landscaping in the Santa Monica Mountains. Be sure to follow your County Fire Department fuel modification plan or guidelines when creating a restoration design. Creating a plan with an experienced fire ecologist or native plant specialist can help make your restoration effort successful in the long run.
We hope everyone who was affected by the Woolsey fire is making progress and healing from this devastating event. With everyone’s help, the Santa Monica Mountains, the place we all call home, will be a beautiful place again, sooner than you know.