Keeping the Delta Coves lagoon in tip-top shape requires an active partnership. The California Division of Boating and Waterways (DBW) is officially responsible for the lagoon and has assigned their Submersed Aquatic Vegetation (SAV) team to oversee regular treatments of the Delta. The latest treatment plan can be found in the lagoon health overview and recap.
As homeowners, you can do your part to protect the Delta by caring for your lagoon zone and riprap – just like you would care for your yard or home. This keeps the lagoon accessible for boats, jet skis, and neighbors looking to enjoy the water.
Homeowner responsibility
Managing your riprap
Riprap is the place where the rocks live between the tip of the yard and the edge of the lagoon waters. Rocks may be dry or wet depending on the tide.
Care for your area:
- Pull weeds – homeowners will find this is easier when they’re small and haven’t taken root.
- Avoid herbicide spray – If you must use it, ensure it is an aquatic safe or natural option and only spray on ‘dry rocks’ away from the waterline.
- Neighbor tip – Pull small weeds when the ground is still soft from a rainstorm.
Handling aquatic vegetation
Keep your lagoon zone clean:
- Pull aquatic vegetation regularly from your dock easement.
- Plan to increase how frequently you remove vegetation during peak growing season. Overgrown vegetation is more effort and more cost to remove.
- Consider coordinating clean-up days with your neighbors. Working together helps the time fly by.
- Dry out vegetation on the dock for 24 hours before placing it in the green debris container or your compost bin.
- Submit a concern to the Community Life team if your neighbors are not caring for their lagoon zone.
- Install a bubbler or water circulator to keep the water flowing between your dock and riprap to make it harder for vegetation and algae to take hold.
- Report suspected harmful algal blooms to the Water Quality Monitoring Board.
- Neighbor tip – Sturdy T-weeders are a great for removing vegetation from the root. Razor rakes are not effective in the long run against Brazilian Waterweed.
Recognizing submersed aquatic vegetation types
While most of these are not yet present in the lagoon, they may root here in the future. Here are the six types of submersed aquatic vegetation the California Division of Boating and Waterways (DBW) oversees.
- Brazilian Waterweed: Most common plant in the lagoon. Look for dense whorls of bright green leaves and white flowers.
- Coontail: Also present in the lagoon. Recognize it by forking green leaves that are bushy or long and sparse.
- Fanwort: Located in Delta waters outside of the lagoon. Look for the finely-divided, fan-shaped leaves.
- Ribbonweed: Located in Delta waters outside of the lagoon. Recognize it by its long, flat leaves.
- Curlyleaf Pondweed: Also located in the Delta waters. Look for wavy edges of the leaves – similar to curly parsley.
- Eurasian Watermilfoil: Located in Delta waters outside of the lagoon. Featherlike leaves whorl around the stem in groups of four.
Frequently Asked Questions
What are the most commonly occuring plant species in the lagoon?
The SAV team requests homeowners watch out for Brazilian Waterweed (egeria densa) and Coontail plants in the lagoon.
Why do we treat for these plants?
These submersed aquatic varieties can make mats in the water or otherwise make Delta waters unnavigable.
Invasive species also disrupt the Delta ecosystem by taking over growth opportunities for native vegetation that provides food and shelter for animals in the area.
Can I just cut the plants off?
Simply put – no. Like plants and weeds on land, aquatic vegetation must be pulled from the root to prevent regrowth. Several species also repropagate or drop new seeds easily - leading to more new growth.
What tools and treatments can I use to remove weeds in my lagoon zone and rip rap?
Neighbors recommend a sturdy T-weeder tool for removing subaquatic vegetation from the roots.
Herbicide treatments are illegal in the lagoon — except for the DBW — and using them carries stiff penalties. If you must use an herbicide to treat weeds on your rip rap, it should be something approved for aquatic use and not applied anywhere near where the tide reaches.
Can I use herbicides in my lagoon zone?
Do not use herbicide treatments in the lagoon or on rocks where the tide can reach them. Offenders face fines up to $30,000 and potential jail time.
Where is my lagoon zone?
Lagoon zones vary from lot to lot. Locate yours on your lot plan - most likely included in your closing documents - or email community life for a copy.
What can I do if my neighbors aren't maintaining their space?
Neighbors not maintaining their lagoon zones is a key piece in the decision to negotiate paid treatment for the lagoon.
If you notice excessive vegetation growth - both on land and in the water - please submit a community concern.
Community Life also monitors lots and sends noncompliance notices to homeowners when necessary.
How does Lake Tech fit into the Delta Coves lagoon care plan?
Lake Tech provides water quality data through sensors on two yellow buoys within the lagoon. Data collects on a website, where the board of directors and homeowners can access it in real time.
Data is also provided to DBW to work in conjunction with DBW monitoring.
Where can I get notices of treatments?
The DBW and SAV teams provide regular alerts of treatments throughout the lagoon to subscribers of their email list. Delta Coves is Site 171.
The DBW will also give DCMC a 2-3 week notice of treatment, at which point a notice will be included in a Delta Coves News email.
Why do I see submersed plant types above water?
During low tide, heavy growth of submersed aquatic vegetation can be seen above the waterline.
What can I do to prevent algae growth?
Algae likes to pop up in spaces where there are no plants – which means it can come up once weeds are pulled from the lagoon. To prevent algae, keep water circulating around and underneath your dock.
Consider installing a circulator and bubbler to encourage water movement.
How do I recognize harmful algal blooms?
Residents may visit the State of California Water Quality Monitoring Board to learn about different types of algae and report suspected harmful algal blooms (HABs).
How long after a DBW treatment should I wait before using the lagoon?
Before Diquat herbicide treatments are administered, the DBW team onsite will ask anyone in the water or on the docks to exit the area.
Neighbors can resume normal water activities in the lagoon or on the docks two hours after treatment is complete.
What happens to vegetation after treatment?
Diquat treatments kill off targeted vegetation. Dead plants disintegrate and settle into the silt or are carried away by the tides.
How many circulators are in the lagoon?
Island camp houses 10 circulators. The developer installed 1 circulator per cove in addition to the bubbler system.
This count does not include circulators in use by homeowners or builders on their lot zones.
Where can I find out if a circulator would be beneficial in my lagoon zone?
Homeowners can obtain a professional consultation if they are on the fence about using a circulator or bubbler.
Neighbors have purchased these from a variety of sources and our water quality partner, Lake Tech, is an option for purchasing as well.
How often should I run a water circulator?
While each lagoon zone may benefit from different timing, Lake Tech recommends starting with running a circulator 8-12 hours a day — during off peak hours — for 2-3 weeks. Take a break for 2-3 weeks, then repeat the cycle.
How do I keep my circulator clean?
To get the optimal performance from your circulator, clean it regularly by soaking it in vinegar. Finish cleaning with a scrub brush to remove calcium buildup.